Chapter III: Ants (3)

Battles between ants of the same species often end
with a lasting alliance, especially when the number of
the workers on both sides is comparatively small. The
wise little animals under such circumstances discover,
much more quickly and better than men, that they can
only destroy each other by fighting, while union would
benefit both parties. Sometimes they drive each other
out of their nests in a quite friendly way. Forel laid
on a table a piece of bark with a nest of the gentle
_Leptothorax acervorum_, and then put on it the
contents of another nest of the same species. The last
comers were by far the more numerous, and soon
possessed themselves of the nest, driving out the
inmates. But the latter did not know whither to go,
and turned back again. They were then seized by their
opponents one after the other, carried away as far as
possible from the nest, and there put down. The
oftener they came back the further were they carried
away. One of the carriers arrived in this fashion at
the edge of the table, and after it had by means of
its feelers convinced itself that it had reached the
end of the world, mercilessly let its burden drop into
the fathomless abyss. It waited a moment to see if it
had attained its object, and then turned back to the
nest. Forel picked up the ant which had fallen on the
floor, and put it down right in front of the returning
ant. The latter repeated the same manoeuvre as at
first, only stretching its neck further over the edge
of the table. He several times reiterated his
experiment, and always with the same result. Later the
two colonies were shut up together in a glass case,
and gradually learned to agree.

At other times, however, warlike ants show great and needless cruelty to one another:--

They slowly pull from their victim, that is rendered
defenceless by wounds, exhaustion, or terror, first
one feeler and then the other, then the legs one after
another, until they at last kill it, or pull it in a
completely mutilated and helpless condition to some
out-of-the-way spot where it perishes miserably. Yet
some compassionate hearts are to be found among the
victors, which only pull the conquered to a distant
place in order to get rid of them, and there let them
go without injuring them.

The following account is also taken from Büchner's 'Mind in Animals,' p. 87:--

The doors are often guarded by special sentries, which
fulfil their important duty in various ways. Forel saw
a nest of the _Colobopsis truncata_, the two or three
very small round openings of which were watched by
soldiers, arranged so that their thick cylindrical
heads stopped them up, just as a cork stops up the
mouth of a bottle. The same observer saw the
_Myrmecina Latreillei_ defend themselves against the
invasions of the slave-making _Strongylognathus_, by
placing a worker at each of the little openings of the
nest, which quite stops up the opening either with
its head or abdomen. The _Camponotus_ species also
defend their nests by stretching their heads in front
of the openings, drawing back the antennæ. Each
approaching enemy thus receives a sharp blow or bite
delivered with the whole weight of the body. MacCook
noticed in the nests of the soon to be described
Pennsylvanian mound-building ants, the employment of
special sentries, which lay watching within the nest
entrances, and sprang out at the first sight of danger
to attack the enemy; and it was wonderful to see with
what swiftness the news of such an alarm spread
through the nest, and how the inhabitants came out _en
masse_ to meet the enemy. The _Lasius_ species defend
their large, strong, and very extensive nests against
hostile attack or sieges with equal courage and skill,
while other timid species seek to fly as speedily as
possible with their larvæ, pupæ, and fruitful queens.
There is, as Forel tells us, a regular barricade
fight. Passage after passage is stopped and defended
to the uttermost, so that the assailants can only
advance step and step. Unless the latter are in an
enormous majority, the struggle may last a very long
time with these tactics. During this time, other
workers are busy preparing subterranean passages
backwards for eventual flight. Generally such passages
are already made, and during a fight a new dome of the
_Lasius_ may be seen rising at a distance, it not
being difficult for them to make this with the help of
their extended subterranean passages and
communications.

The _F. exsecta_ or _pressilabris_ fights in a
peculiar way, which is due to care of their small and
very tender bodies. It avoids all single combats, and
always fights in closed ranks. Only when it thinks
victory secure does it spring on its enemy's back. But
its chief strength lies in the fact that many together
always attack a foe. They nail down their opponent by
seizing its legs and holding them firmly to the
ground, while a comrade springs on the back of the
defenceless creature and tries to bite through its
neck. But if threatened the holders sometimes take
flight, and so it happens that in battles between the
_exsectæ_ and the much stronger _pratenses_ not a few
of the latter are seen running about with a small
enemy clutching their shoulders, and making violent
efforts to tear the neck of its foe. If the bearer is
then seized with cramp, the nervous cord has been
injured. On the other hand, if an _exsecta_ is seized
by the back by a _pratensis_ it is at once lost.

The tactics of the turf ants resemble those of the
_exsectæ_, three or four of them seizing an opponent
and pulling off his legs. In similar fashion the
attack of the _Lasius_ species is chiefly directed
against the legs of its enemies, three, four, or five
uniting in the effort. They understand barricade
fighting particularly well in their large well-built
dwellings, and if it comes to the worst fly by
subterranean passages. They are feared by most ants on
account of their numerical superiority. Forel one day
poured the contents of ten nests of _pratenses_ in
front of a tree trunk inhabited by _Lasius
fuliginosus_ (jet ant). The siege at once began; but
the jet ants called in help from the nests connected
with their colony, and thick black columns were at
once seen coming out from the surrounding trees. The
_pratenses_ were obliged to fly, and left behind them
a mass of dead as well as their pupæ, which last were
carried off by the victors to their nests to be eaten.

Battles, however, are not confined to species of ants having warlike and slave-making habits. The agricultural ants likewise at times wage fierce wars with one another. The importance of seeds to these ants, and the consequent value which they set upon them, induce the animals, when supplies are scarce, to plunder each other's nests. Thus Moggridge says,--

By far the most savage and prolonged contests which I
have witnessed were those in which the combatants
belong to two different colonies of the same
species. . . . The most singular contests are those
which are waged for seeds by _A. barbara_, when one
colony plunders the stores of an adjacent nest
belonging to the same species, the weaker nest making
prolonged though, for the most part, inefficient
attempts to recover their property.

In the case of the other species of ant which I have
watched fighting, the strife would last but a short
time--a few hours or a day--but _A. barbara_ will
carry on the battle day after day and week after week.
I was able to devote a good deal of time to watching
the progress of a predatory war of this kind, waged by
one nest of _barbara_ against another, and which
lasted for forty-six days, from January 18 to March 4!

I cannot of course declare positively that no
cessation of hostilities may have taken place during
the time, but I can affirm that whenever I visited the
spot--and I did so on twelve days, or as nearly as
possible twice a week--the scene was one of war and
spoliation such as that which I shall now describe.

An active train of ants, nearly resembling an ordinary
harvesting train, led from the entrance of one nest to
that of another lower down the slope, and fifteen feet
distant; but on closer examination it appeared that
though the great mass of seed-bearers were travelling
towards the upper nest, some few were going in the
opposite direction and making for the lower. Besides
this, at intervals, combats might be seen taking
place, one ant seizing the free end of a seed carried
by another, and endeavouring to wrench it away, and
then frequently, as neither would let go, the stronger
ant would drag seed and opponent towards its nest. At
times other ants would interfere and seize one of the
combatants and endeavour to drag it away, this often
resulting in terrible mutilations, and especially in
the loss of the abdomen, which would be torn off while
the jaws of the victim retained their indomitable
bull-dog grip upon the seed. Then the victor might be
seen dragging away his prize, while its adversary,
though now little more than a head and legs, offered a
vigorous though of course ineffectual resistance. I
frequently observed that the ants during these
conflicts would endeavour to seize one another's
antennæ, and that if this were effected, the ant thus
assaulted would instantly release his hold, whether of
seed or adversary, and appear utterly discomfited. No
doubt the antennæ are their most sensitive parts, and
injuries inflicted on these organs cause the greatest
pain.

It was not until I had watched this scene for some
days that I apprehended its true meaning, and
discovered that the ants of the upper nest were
robbing the granaries of the lower, while the latter
tried to recover the stolen seeds both by fighting for
them and by stealing seeds in their turn from the nest
of their oppressors. The thieves, however, were
evidently the stronger, and streams of ants laden with
seeds arrived safely at the upper nest, while close
observation showed that very few seeds were
successfully carried on the reverse journey into the
lower and plundered nest.

Thus when I fixed my attention on one of these robbed
ants surreptitiously making its exit with the seed
from the thieves' nest, and having overcome the
opposition and dangers met with on its way, reaching,
after a journey which took six minutes to accomplish,
the entrance to its own home, I saw that it was
violently deprived of its burden by a guard of ants
stationed there apparently for the purpose, one of
whom instantly started off and carried the seed all
the way back again to the upper nest.

This I saw repeated several times.

After March 4 I never saw any acts of hostility
between these nests, though the robbed nest was not
abandoned. In another case of the same kind, however,
where the struggle lasted thirty-one days, the robbed
nest was at length completely abandoned, and on
opening it I found all the granaries empty with one
single exception, and this one was pierced by the
matted roots of grasses and other plants, and must
therefore have been long neglected by the ants.
Strangely enough, not one of the seeds in this
deserted granary showed traces of germination.

No doubt some very pressing need is the cause of these
systematic raids in search of accumulations of seeds,
and there can be little doubt that the requirements of
distinct colonies of ants of the same species are
often different even at the same season and date. Thus
these warring colonies of ants were active on many
days when the majority of the nests were completely
closed; and I have even seen these robbers staggering
along, enfeebled by the cold, and in wind and rain,
when all other ants were safe below ground.

The agricultural ants of Texas do not appear to be less pugnacious than their European congeners. Thus MacCook says:--

A young community has sometimes to struggle into
permanent prosperity through many perils. The
following example is found in the unpublished Lincecum
manuscripts. One day a new ant-city was observed to be
located within ten or twelve yards of a
long-established nest, a distance that the doctor
thought would prove too near for peaceable
possession--for the agriculturals seem to pre-empt a
certain range of territory around their formicary as
their own, within which no intrusion is allowed. He
therefore concluded to keep these nests under close
observation, and visited them frequently. Only a day
or two had elapsed before he found that the
inhabitants of the old city had made war upon the new.
They had surrounded it in great numbers, and were
entering, dragging out and killing the citizens. The
young colonists, who seemed to be of less size than
their adversaries, fought bravely, and,
notwithstanding they were overwhelmed by superior
numbers, killed and maimed many of their assailants.
The parties were scattered in struggling pairs over a
space ten or fifteen feet around the city gate, and
the ground was strewed with many dead bodies. The new
colonists aimed altogether at cutting off the legs of
their larger foes, which they accomplished with much
success. The old-city warriors, on the contrary,
gnawed and clipped off the heads and abdomens of their
enemies. Two days afterward the battlefield was
revisited, and many ants were found lying dead tightly
locked together by legs and mandibles, while hundreds
of decapitated bodies and severed heads were strewed
over the ground.

Another example, which is given in the published
paper, is quite similar, and had like result. In
forty-eight hours the old settlers had exterminated
the new. The distance between the nests was about 20
feet. While the young colonists remained in
concealment they were not disturbed, but as soon as
they began to clear away their open disk war was
declared.

MacCook, however, says that 'these ants are not always so jealous of territorial encroachment, or at least must have different standards of rights.' For he observed many cases of nests situated within twenty, and even ten feet of one another, without a battle ever occurring between members of the two communities. Therefore, without questioning the accuracy of Lincecum's observations--which, indeed, present no scope for inaccuracy--he adds, 'That neighbouring ants, like neighbouring nations of civilised men, will fall out and wage war Lincecum's examples show. Perhaps we should be quite as unsuccessful in case of these ants as of our human congeners, should we seek a sufficient reason for these wars, or satisfactory cause for these differences in dealing with neighbours which appear from the comparison of Lincecum's observations with mine.'

In connection with the wars of these ants, the following quotations may also be made from the same author:--

The erratic ants do not appear to be held as common
enemies by the agriculturals, and they are even
permitted to establish their formicaries within the
limits of the open disk. Sometimes, however, the
diminutive hillocks which mark the entrance to an
erratic ant-nest multiply beyond the limit of the
agriculturals' forbearance. But they do not declare
war, nor resort to any personal violence.
Nevertheless, they get rid of them, oddly enough, by a
regular system of vexatious obstructions. They
suddenly conclude that there is urgent demand for
improving their public domain. Forthwith they sally
forth in large numbers, fall eagerly to work gathering
the little black balls which are thrown up by the
earth-worms in great quantities everywhere in the
prairie soil, which they bring and heap upon the paved
disk until all the erratic ant-nests are covered! The
entire pavement is thus raised an inch or so, and
pains are taken to deposit more balls upon and around
the domiciles of their tiny neighbours than elsewhere.
The erratics struggle vigorously against this Pompeian
treatment; they bore through the avalanche of balls,
only to find barriers laid in their way. The
obstructions at length become so serious that it is
impossible to keep the galleries open. The dwarfs
cease to contend against destiny, and, gathering
together their household stores, quietly evacuate the
premises of the inhospitable giants. It is the triumph
of the policy of obstruction, a bloodless but
effectual opposition.

Lastly, MacCook records the history of an interesting engagement which he witnessed between two nests of _Tetramorium cæspitum_. It took place between Broad Street and Penn Square in Philadelphia, and lasted for nearly three weeks. Although all the combatants belonged to the same species, however great the confusion of the fight, friends were always distinguished from foes--apparently by contact of antennæ.

_Habit of keeping Domestic Pets._--Many species of ants display the curious habit of keeping in their nests sundry kinds of other insects, which, so far as observation extends, are of no benefit to the ants, and which therefore have been regarded by observers as mere domestic pets. These 'pets' are for the most part species which occur nowhere else except in ants' nests, and each species of 'pet' is peculiar to certain species of ants. Thus Moggridge found 'a large number of a minute shining brown beetle moving about among the seeds' in the nests of the harvesting ant of the south of Europe, 'belonging to the scarce and very restricted genus _Colnocera_, called by Kraatz _C. attæ_, on account of its inhabiting the nests of ants belonging to the genus _Atta_.' He also observed inhabiting the same nests a minute cricket 'scarcely larger than a grain of wheat' (_Gryllus myrmecophilus_), which had been previously observed by Paolo Savi in the nests of several species of ants in Tuscany, where it lived on the best terms with its hosts, playing round the nests in warm weather, and retiring into them in stormy weather, while allowing the ants to carry it from place to place during migrations. Again, Mr. Bates observes that 'some of the most anomalous forms of coleopterous insects are those which live solely in the nests of ants.' Sir John Lubbock also, and other observers whom we need not wait to cite, mention similar facts. The Rev. Mr. White says that altogether 40 distinct species of Coleoptera, most of which he has in his own collection, are known to inhabit the nests of various species of ants, and to occur nowhere else.

As in all these cases the ants live on amicable terms with their guests, and in some cases even bestow labour upon them (as in carrying them from one nest to another during migration), it is evident that these insects are not only tolerated, but fostered by the ants. Moreover, as it seems absurd to credit ants with any mere fancy or caprice such as that of keeping pets, we can only conclude that these insects, like the aphides, are of some use to their hosts, although we are not yet in a position to surmise what this use can be.

_Habits of Sleep and Cleanliness._--It is probable that all species of ants enjoy periods of true sleep alternating with those of activity; but actual observations on this subject have only been made on two or three species. The following is MacCook's account of these habits in the harvesting ant of Texas:--

The observation upon the ants now before me began at 8
o'clock; at 11 P.M. the cluster had nearly dissolved,
only a few being asleep. To illustrate the soundness
of this sleep I take the quill pen with which I write,
and apply the feather end of it to an ant who is
sleeping upon the soil. She has chosen a little oval
depression in the surface, and lies with abdomen upon
the raised edge, and face toward the lamp. Her legs
are drawn up close to the body. She is perfectly
still. I gently draw the feather tip along the body,
stroking 'with the fur,' if I may so say. There is no
motion. Again and again this action is repeated, the
stroke gradually being made heavier, although always
quite gentle. Still there is no change. The strokes
are now directed upon the head, with the same result.
Now the tip is applied to the neck, the point at which
the head is united to the pro-thorax, with a waving
motion intended to produce a sensation of tickling.
The ant remains motionless. After continuing these
experiments for several minutes, I arouse the sleeper
by a sharp touch of the quill. She stretches out her
head, then her legs, which she also shakes, steps
nearer to the light, and begins to cleanse herself in
the manner already described. This act invariably
follows the waking of ants from sleep. The above
description applies to the general habit of somnolence
as observed upon the two named species of harvesting
ants for nearly four months. I have often applied the
quill, and even the point of a lead pencil, to the
sleeping Floridians without breaking their slumber.
There are some other details which have not appeared
in the behaviour of the individual just put under
observation.

Thus, I have several times seen the ants (_Crudelis_)
_yawning_ after awaking. I use this word for lack of
one which more accurately expresses the behaviour. The
action is very like that of the human animal; the
mandibles are thrown open with the peculiar muscular
strain which is familiar to all readers; the tongue
also is sometimes thrust out, and the limbs stretched
with the appearance, at least, of that tension which
accompanies the yawn in the genus _homo_. During sleep
the antennæ have a gentle, quivering, apparently
involuntary motion, which seemed to me, at times, to
have the regularity of breathing. I also often noted
an occasional regular lifting up and setting down of
the fore-feet, one leg after another, with almost a
rhythmic motion.

The length of time during which sleep is prolonged
appears to vary according to circumstances and,
perhaps, organism. The large head-soldiers of the
Floridian harvesters appear to have a more sluggish
nature than the smaller workers. Their sleep is longer
and heavier. The former fact the watch readily
determined. The latter appeared from the greater
stolidity of the creatures under disturbance. While
the ants of one group are taking sleep others may be
busy at work, and these stalk among and over the
sleepers, jostling them quite vigorously at times.
Again, new members occasionally join the group, and,
in their desire to get close up to the heat and light,
crowd their drowsy comrades aside. I have seen ants
who had been at work in the galleries drop their
pellets, push thus into the cluster, and presently be
apparently sound asleep. This rough treatment is
invariably received with perfect good humour, as are
like jostlings when the ants are awake. I have never
seen the slightest display of anger or attempt to
resent disturbance even under these circumstances, so
peculiarly calculated to excite the utmost irritation
in men. But of course some of the sleepers are
aroused. They change position a little, or give
themselves a brief combing, and then resume their nap,
unless, indeed, they are satisfied. In watching these
movements it was quite evident that the Florida
soldiers were far less easily disturbed than their
smaller fellows. They slept on stolidly while all the
others were in agitation around them. Moreover, their
very appearance, particularly when awaking out of
sleep, indicated the greater sluggishness of their
temperament in this respect.

The ordinary duration of sleep MacCook takes to be about three hours.

Ants, like many other insects, are in the habit of cleaning themselves, being, like them, provided by nature with combs and brushes, &c., for the purpose. But, unlike other insects, several species of ants are also in the habit of assisting each other in the performance of their toilet. The author last quoted gives the following account of this process in the genus _Atta_:--

We take a couple; the cleanser has begun at the face,
which is licked thoroughly, even the mandibles being
cared for, they being held apart for convenient
manipulation. From the face the cleanser passes to the
thorax, thence to the haunch, and so along the first
leg, along the second and third in the same manner,
around to the abdomen, and thence up the other side of
the ant to the head. A third ant approaches and joins
in the friendly task, but soon abandons the field to
the original cleanser. The attitude of the cleansed
all this while is one of intense satisfaction, quite
resembling that of a family dog when one is scratching
the back of his neck. The insect stretches out her
limbs, and, as her friend takes them successively into
hand, yields them limp and supple to her manipulation;
she rolls gently over upon her side, even quite over
upon her back, and with all her limbs relaxed presents
a perfect picture of muscular surrender and ease. The
pleasure which the creatures take in being thus
'combed' and 'sponged' is really enjoyable to the
observer. I have seen an ant kneel down before another
and thrust forward the head, drooping, quite under the
face, and lie there motionless, thus expressing, as
plainly as sign-language could, her desire to be
cleansed. I at once understood the gesture, and so did
the supplicated ant, for she at once went to work. If
analogies in nature-studies were not so apt to be
misleading, one might venture to suggest that our
insect friends are thus in possession of a modified
sort of Emmetonian Turkish bath.

The acrobatic skill of these ants, which has often
furnished me amusement, and which I shall yet further
illustrate, was fully shown one morning in these
offices of ablution. The formicary was taken from the
study, where the air had become chilled, and placed in
an adjoining chamber upon the hearth, before an
open-grate fire. The genial warmth was soon diffused
throughout the nest, and aroused its occupants to
unusual activity. A tuft of grass in the centre of the
box was presently covered with them. They climbed to
the very top of the spires, turned round and round,
hanging by their paws, not unlike gymnasts performing
upon a turning-bar. They hung or clung in various
positions, grasping the grass blade with the third and
fourth pairs of legs, which were spread out at length,
cleansing their heads with the fore-legs or bending
underneath to comb and lick the abdomen. Among these
ants were several pairs, in one case a triplet,
engaged in the cleansing operation just described. The
cleanser clung to the grass, having a fore-leg on one
side and a hind leg on the other side of the stem,
stretched out at full length, while the cleansed hung
in a like position below, and reached over and up,
submitting herself to the pleasant process. As the
progress of the act required a change of posture on
the part of both insects, it was made with the utmost
agility.

Similarly, Bates thus describes the cleansing process in another genus of ants (_Ecitons_):--

Here and there an ant was seen stretching forth first
one leg and then another, to be brushed and washed by
one or more of its comrades, who performed the task by
passing the limb between the jaws and tongue,
finishing by giving the antennæ a friendly wipe.

_Habits of Play and Leisure._--The life of ants is not all work, or, at least, is not so in all species; for in some species, at any rate, periods of recreation are habitually indulged in.

Büchner('Geistesleben der Thiere,' p. 163) gives the following abstract of Huber's celebrated observations in this connection:--

It was of the _pratensis_ that Huber wrote the
observations touching its gymnastic sports which
became so famous. He saw these ants on a fine day
assembled on the surface of their nest, and behaving
in a way that he could only explain as simulating
festival sports or other games. They raised themselves
on their hind legs, embraced each other with their
fore-legs, seized each other by the antennæ, feet, or
mandibles, and wrestled--but all in friendliest
fashion. They then let go, ran after each other, and
played hide-and-seek. When one was victorious, it
seized all the others in the ring, and tumbled them
over like ninepins.

This account of Huber's found its way into many
popular books, but in spite of its clearness won
little credence from the reading public. 'I found it
hard to believe Huber's observation,' writes Forel,
'in spite of its exactness, until I myself had seen
the same.' A colony of the _pratensis_ several times
gave him the opportunity when he approached it
carefully. The players caught each other by the feet
or jaws, rolled over each other on the ground like
boys playing, pulled each other inside the entrances
of their nest, only to come out again, and so on. All
this was done without bad temper, or any spurting of
poison, and it was clear that all the rivalry was
friendly. The least breath from the side of the
observer was enough to put an end to the games. 'I
understand,' continues Forel, 'that the affair must
seem marvellous to those who have not seen it,
especially when we remember that sexual attraction can
here play no part.'

MacCook also gives an account of habits of play as indulged in among ants of the other Hemisphere:--

At one formicary half a dozen or more young queens
were out at the same time. They would climb up a large
pebble near the gate, face the wind, and assume a
rampant posture. Several having ascended the stone at
one time, there ensued a little playful
passage-at-arms as to position. They nipped each other
gently with the mandibles, and chased one another from
favourite spots. They, however, never nipped the
workers. These latter evidently kept a watch upon the
sportive princesses, occasionally saluted them with
their antennæ in the usual way, or touched them at the
abdomen, but apparently allowed them full liberty of
action.

As to leisure, Bates writes:--

The life of these Ecitons is not all work, for I
frequently saw them very leisurely employed in a way
that looked like recreation. When this happened the
place was always a sunny nook in the forest. The main
column of the army and the branch columns, at these
times, were in their ordinary relative positions; but
instead of pressing forward eagerly and plundering
right and left, they seemed to have been all smitten
with a sudden fit of laziness. Some were walking
sternly about, others were brushing their antennæ with
their fore-feet; but the drollest sight was their
cleaning each other. [Here follows the above-quoted
passage.] The actions of these ants looked like simple
indulgence in idle amusement. . . . It is probable
that these hours of relaxation and cleaning may be
indispensable to the effective performance of their
harder burdens; but whilst looking at them, the
conclusion that the ants were engaged merely in play
was irresistible.[31]

_Funereal Habits._--In another connection it has already been stated that Sir John Lubbock found his ants to be very careful in disposing of the dead bodies of their comrades. This habit seems to be pretty general among many species of ants, and is no doubt due to sanitary requirements, thus becoming developed as a beneficial instinct by natural selection. The funereal habits of the agricultural ant are thus related by MacCook:[32]--

There is nothing which is apt to awaken deeper
interest in the life-history of ants than what may
properly be called their funereal habits. All species
whose manners I have closely observed are quite alike
in their mode of caring for their own dead, and for
the dry carcasses of aliens. The former they appear to
treat with some degree of reverence, at least to the
extent of giving them a sort of sepulture without
feeding upon them. The latter, after having exhausted
the juices of the body, they usually deposit together
in some spot removed from the nest. I did not see any
of the 'cemeteries' of the agricultural ant upon the
field, nor, indeed, observe any of their behaviour
towards the dead, but my artificial nests gave me some
insight of this. In the first colony had been placed
eight agriculturals of another nest, which were
literally cut to pieces. Very soon after the ants were
comfortably established in their new home, a number of
them laid hold upon these _disjecta membra_, and began
carrying them back and forth around the formicarium.
The next day this continued, and several of their own
number who had died were being treated in like
manner. Back and forth, up and down, into every corner
of the box the bearers wandered, the very embodiment
of restlessness. For four days this conduct continued
without any intermission. No sooner would a body or
fragment thereof be dropped by one bearer than another
would take it up and begin the restless circuit. The
difficulty, I easily understood, was that there was no
point to be found far enough removed from the
living-rooms of the insects in which to inter these
dead. Their desire to have their dead buried out of
their sight was strong enough to keep them on this
ceaseless round, apparently under the continuous
influence of the hope that something might turn up to
give them a more satisfactory burial-ground. It does
not appear greatly to the credit of their wisdom that
they were so long discovering that they were limited
to a space beyond their power to enlarge. When,
however, this fact was finally recognised they gave
their habit its utmost bent, and began to deposit the
carcasses in the extreme corner of the flat, as
distant as possible from the galleries on the terrace
above. Here a little hollow was made in the earth,
quite up against the glass, wherein a number of bodies
were laid. Portions of bodies were thrust into the
chinks formed in the dry sod. This flat became the
permanent charnel-house of the colony, and here, in
corners, crevices, and holes, for the most part out of
sight, but not always so, the dead were deposited. But
the living never seemed quite reconciled to their
presence. Occasionally, restless resurrectionists
would disentomb the dead, shift them to another spot,
or start them once more upon their unquiet wanderings.
Even after the establishment of this cemetery, the
creatures did not seem able to lay away their newly
deceased comrades--for there were occasional deaths in
the formicary--without first indulging in this
funereal promenade.

In the formicaries established in glass jars, both of
_barbatus_ and _crudelis_, the same behaviour
appeared. So great was the desire to get the dead
outside the nest, that the bearers would climb up the
smooth surface of the glass to the very top of the
jar, laboriously carrying with them a dead ant. This
was severe work, which was rarely undertaken except
under the influence of this funereal enthusiasm. The
jar was very smooth and quite high. Falls were
frequent, but patiently the little 'undertaker' would
follow the impulse of her instinct, and try and try
again. Finally, as in the large box, the fact of a
necessity seemed to dawn upon the ants, and a portion
of the surface opposite from the entrance to the
galleries, and close up against the glass, was used
as burial-ground and sort of kitchen-midden, where all
the refuse of the nest was deposited. Mrs. Treat has
informed me that her artificial nests of _crudelis_
behaved in precisely the same way.

An interesting fact in the funereal habits of _Formica
sanguinea_ was related to me by this lady. A visit was
paid to a large colony of these slave-makers, which is
established on the grounds adjoining her residence at
Vineland, New Jersey. I noticed that a number of
carcasses of one of the slave species, _Formica
fusca_, were deposited together quite near the gates
of the nest. These were probably chiefly the dry
bodies of ants brought in from recent raids. It was
noticed that the dead ants were all of one species,
and thereupon Mrs. Treat informed me that the red
slave-makers never deposited their dead with those of
their black servitors, but always laid them by
themselves, not in groups, but separately, and were
careful to take them a considerable distance from the
nest. One can hardly resist pointing here another
likeness between the customs of these social
hymenopters and those of human beings, certain of whom
carry their distinctions of race, condition, or
religious caste, even to the gates of the cemetery in
which the poor body moulders into its mother dust!

It will be observed that none of these accounts furnish evidence of ants burying their dead, as Pliny asserts to have been the case with ants in the south of Europe. In the Proceedings of the Linnæan Society, however (1861), there is a very definite account of such a practice as obtaining among the ants of Sydney; and although it is from the pen of an observer not well known, the observation seems to have been one about which there could scarcely have been a mistake. The observer was Mrs. Hutton, and this is her account. Having killed a number of 'soldier ants,' and returning half an hour afterwards to the place where the dead bodies were lying, she says:

I saw a large number of ants surrounding the dead
ones. I determined to watch their proceedings closely.
I followed four or five that started off from the rest
towards a hillock a short distance off, in which was
an ants' nest. This they entered, and in about five
minutes they reappeared, followed by others. All fell
into rank, walking regularly and slowly two by two,
until they arrived at the spot where lay the dead
bodies of the soldier ante. In a few minutes two of
the ants advanced and took up the dead body of one of
their comrades; then two others, and so on, until all
were ready to march. First walked two ants bearing a
body, then two without a burden; then two others with
another dead ant, and so on, until the line was
extended to about forty pairs, and the procession now
moved slowly onwards, followed by an irregular body of
about two hundred ants. Occasionally the two laden
ants stopped, and laying down the dead ant, it was
taken up by the two walking unburdened behind them,
and thus, by occasionally relieving each other, they
arrived at a sandy spot near the sea. The body of ants
now commenced digging with their jaws a number of
holes in the ground, into each of which a dead ant was
laid, where they now laboured on until they had filled
up the ants' graves. This did not quite finish the
remarkable circumstances attending this funeral of the
ants. Some six or seven of the ants had attempted to
run off without performing their share of the task of
digging; these were caught and brought back, when they
were at once attacked by the body of ants and killed
upon the spot. A single grave was quickly dug, and
they were all dropped into it.

The Rev. W. Farren White also, in his papers on ants published in the 'Leisure Hour' (1880), after alluding to the above case, corroborates it by some interesting observations of his own. He says:--

Several of the little sextons I observed with dead in
their mandibles, and one in the act of burying a
corpse. . . . I should mention that the dead are not
interred without considerable difficulty, in
consequence of the sides of the trays being almost
perpendicular. The work of the sextons continued until
no dead bodies remained upon the surface of the nest,
but all were interred in the extramural cemeteries.
Afterwards I removed the trays, and turned the
contents of the formicarium upside down, and then I
placed six trays on the surface of the earth, two of
which I filled with sugar for food. All six were used
freely as cemeteries, being crowded with the corpses
of the little people and their young, the larvæ which
had perished in the disruption of their home.

I have noticed in one of my formicaria a subterranean
cemetery, where I have seen some ants burying their
dead by placing earth above them. One ant was
evidently much affected, and tried to exhume the
bodies, but the united exertions of the yellow sextons
were more than sufficient to neutralise the effort of
the disconsolate mourner. The cemetery was now
converted into a large vault, the chamber where the
dead were placed, together with the passage which led
to it, being completely covered in.

_Habits Peculiar to Certain Species._

_Leaf-cutting Ants of the Amazon_ ([OE]codoma cephalotes).--The mode of working practised by these ants is thus described by Mr. Bates:--

They mount a tree in multitudes. . . . Each one places
itself on the surface of a leaf, and cuts with its
sharp scissor-like jaws a nearly semicircular incision
on the upper side; it then takes the edge between its
jaws, and by a sharp jerk detaches the piece.
Sometimes they let the leaf drop to the ground, where
a little heap accumulates, until carried off by
another relay of workers; but generally each marches
off with the piece it has operated on, and as all take
the same road to the colony, the path they follow
becomes in a short time smooth and bare, looking like
the impression of a cart-wheel through the herbage.

Each ant carries its semicircular piece of leaf upright over its head, so that the home-returning train is rendered very conspicuous. Nearer observation shows that this home-returning or ladened train of workers keeps to one side of the road, while the outgoing or empty-handed train keeps to the other side; so that on every road there is a double train of ants going in opposite directions. When the leaves arrive at the nest they are received by a smaller kind of workers, whose duty it is to cut up the pieces of leaf into still smaller fragments, whereby the leaves seem to be better fitted for the purpose to which, as we shall presently see, they are put. These smaller workers never take any part in the outdoor labours; but they occasionally leave the nest, apparently for the sole purpose of obtaining air and exercise, for when they leave the nest they merely run about doing nothing, and frequently, as if in mere sport, mount some of the semicircular pieces of leaf which the carrier ants are taking to the nest, and so get a ride home.

From his continued observation of these ants, Bates concludes--and his opinion has been corroborated by that both of Belt and Müller--that the object of all this labour is highly interesting and remarkable. The leaves when gathered do not themselves appear to be of any service to the ants as food; but when cut into small fragments and stored away in the nests, they become suited as a nidus for the growth of a minute kind of fungus on which the ants feed. We may therefore call these insects the 'gardening ants,' inasmuch as all their labour is given to the rearing of nutritious vegetables on artificially prepared soil. They are not particular as to the material which they collect and store up for soil, provided that it is a material on which the fungus will grow. Thus they are very partial to the inside white rind of oranges, and will carry off the flowers of certain shrubs while leaving the leaves untouched. But, to quote again from Bates,--

They are very particular about the ventilation of
their underground chambers, and have numerous holes
leading up to the surface from them. These they open
out or close up, apparently to keep up a regular
degree of temperature below. The great care they take
that the pieces of leaves they carry into the nest
should be neither too dry nor too damp, is also
consistent with the idea that the object is the growth
of a fungus that requires particular conditions of
temperature and moisture to ensure its vigorous
growth. If a sudden shower should come on, the ants do
not carry the wet pieces into the burrows, but throw
them down near the entrances. Should the weather clear
up again, these pieces are picked up when nearly
dried, and taken inside: should the rain, however,
continue, they get sodden down into the ground, and
are left there. On the contrary, in dry and hot
weather, when the leaves would get dried up before
they could be conveyed to the nest, the ants, when in
exposed situations, do not go out at all during the
hot hours, but bring in their leafy burdens in the
cool of the day and during the night. As soon as the
pieces of leaves are carried in they must be cut up by
the small class of workers into little pieces. Some of
the ants make mistakes, and carry in unsuitable
leaves. Thus grass is always rejected by them, but I
have seen some ants, perhaps young ones, carrying
leaves of grass; but after a while these pieces are
always brought out again and thrown away. I can
imagine a young ant getting a severe ear-wigging from
one of the major-domos for its stupidity.

When a nest is disturbed and the masses of ant-food
spread about, the ants are in great concern to carry
every morsel of it under shelter again; and sometimes,
when I had dug into a nest, I found the next day all
the earth thrown out filled with little pits, that the
ants had dug into it to get out the covered-up food.
When they migrate from one part to another, they also
carry with them all the ant-food from their old
habitations.

In Büchner's 'Geistesleben der Thiere' there is published an interesting description of the habits of these ants, which was communicated to the author by Dr. Fr. Ellendorf of Wiedenbrück, who has lived many years in Central America. Dr. Ellendorf says that--

It would be quite impossible for them to creep even
through short grass with loads on their heads for
miles. They therefore bite off the grass close to the
ground for a breadth of about five inches, and throw
it on one side. Thus a road is constructed, which is
finally made quite smooth and even by the continual
passing to and fro of millions upon millions night and
day. . . . If the road is looked down upon from a height
with these millions thickly pressed together, and all
moving along with their green bannerets over their
heads, it looks as though a giant green snake were
gliding slowly along the ground; and this picture is
all the more striking in that all these bannerets are
swaying backwards and forwards.[33]

This observer made the experiment of interrupting the advance of a column of these ants, with the interesting result which he describes:--

I wished to see how they would manage if I put an
obstacle in their way. Thick high grass stood on
either side of their narrow road, so that they could
not pass through it with the load on their heads. I
placed a dry branch, nearly a foot in diameter,
obliquely across their path, and pressed it down so
tightly on the ground that they could not creep
underneath. The first comers crawled beneath the
branch as far as they could, and then tried to climb
over, but failed owing to the weight on their heads.
Meanwhile the unloaded ants from the other side came
on, and when these succeeded in climbing over the
bough there was such a crush that the unladen ants had
to clamber over the laden, and the result was a
terrible muddle. I now walked along the train, and
found that all the ants with their bannerets on their
heads were standing still, thickly pressed together,
awaiting the word of command from the front. When I
turned back to the obstacle, I saw with astonishment
that the loads had been laid aside by more than a
foot's length of the column, one imitating the other.
And now work began on both sides of the branch, and in
about half an hour a tunnel was made beneath it. Each
ant then took up its burden again, and the march was
resumed in the most perfect order.

A migration of these ants is thus described by the same observer:--

The road led towards a cocoa plantation, and here I
soon discovered the building which I afterwards
visited daily. As I again went thither one day I was
met, at a considerable distance from the nest, by a
closely pressed column coming thence, and all the ants
laden with leaves, beetles, pupæ, butterflies, &c.;
the nearer I came to the nest, the greater was the
activity. It was soon plain to me that the ants were
in the act of leaving their dwelling, and I walked
along the train to discover the new abode. They had
gone for some distance along the old road, and had
then made a new one through the grass to a cooler
place, lying rather higher. The grass on the new road
was all bitten off close to the ground, and thousands
were busy carrying the path on to the new building. At
the new home itself was an unusual stir of life. There
were all sorts of labourers--architects, builders,
carpenters, sappers, helpers. A number were busy
digging a hole in the ground, and they carried out
little pellets of earth and laid them together on end
to make a wall. Others drew along little twigs,
straws, and grass-stalks, and put them near the place
of building. I was anxious to know why they had
quitted their old home, and when the departure was
complete, I dug it up with a spade. At a depth of
about a foot and a half I found several tunnels of a
large marmot species, the terror of cocoa planters,
because in making their passages they gnaw off the
thickest roots of the cocoa plants. The interior of
the ant-hill had apparently fallen in through these
mines. Unfortunately I was unable to follow further
the progress of the new building, for I was obliged to
leave the next day for San Juan del Sur. When I
returned at the end of a week the building was
finished, and the whole colony was again busy with the
leaves of the coffee plants.

_Harvesting Ants_ (Atta).--The ants which, so far as at present known, practise the peculiar and distinctive habits to be described under this division belong for the most part to one genus, _Atta_, which, however, comprises a number of species distributed in localised areas over all the four quarters of the globe. Hitherto nineteen species have been detected as having the habits in question. These consist of gathering nutritious seeds of grasses during summer, and storing them in granaries for winter consumption. We owe our present knowledge concerning these insects to Mr. Moggridge,[34] who studied them in the south of Europe, Dr. Lincecum,[35] and Mr. MacCook,[36] who studied them in Texas, and Colonel Sykes[37] and Dr. Jerdon,[38] who made some observations upon them in India. They also occur scattered over a great part of Europe and in Palestine, where they were clearly known to Solomon and other classical writers of antiquity,[39] whose claim to accurate observation, although long disputed (owing to the authority of Huber), has now been amply vindicated.

Mr. Moggridge, who was a careful and industrious observer, found the following points of interest in the habits of the European harvesters. From the nest in various directions there proceed outgoing trains, which may be from twenty to thirty or more yards in length, and each consists of a double row of ants, moving, like the leaf-cutting ants, in opposite directions. Those in the outgoing row are empty-handed, while those in the incoming row are laden. But here the burdens are grass seeds. The roads terminate in the foraging ground, or ant-fields, and the insects composing the columns there become dispersed by hundreds among the seed-yielding grasses. The following is their method of collecting seeds; I quote from Moggridge:--