Volume 2 — LETTER XVII. (continued 2)

The above observations, with respect to the indolence of our slave-dealers, relate principally to the rufescent species; for the sanguine ants are not altogether so listless and helpless; they assist their negroes in the construction of their nests, they collect their sweet fluid from the Aphides; and one of their most usual occupations is to lie in wait for a small species of ant, on which they feed; and when their nest is menaced by an enemy, they show their value for these faithful servants by carrying them down into the lowest apartments, as to a place of the greatest security. Sometimes even the rufescents rouse themselves from the torpor that usually benumbs them. In one instance, when they wished to emigrate from their own to a deserted nest, they reversed what usually takes place on such occasions, and carried all their negroes themselves to the spot they had chosen. At the first foundation also of their societies by impregnated females, there is good reason for thinking, that, like those of other species[86], they take upon themselves the whole charge of the nascent colony. I must not here omit a most extraordinary anecdote related by M. Huber. He put into one of his artificial formicaries pupæ of both species of the slave-collecting ants, which, under the care of some negroes introduced with them, arrived at their imago state, and lived together under the same roof in the most perfect amity.

These facts show what effects education will produce even upon insects; that it will impart to them a new bias, and modify in some respects their usual instincts, rendering them familiar with objects which, had they been educated at home, they would have feared, and causing them to love those whom in that case they would have abhorred.—It occasions, however, no further change in their character, since the master and slave, brought up with the same care and under the same superintendence, are associated in the mixed formicary under laws entirely opposite[87].

Unparalleled and unique in the animal kingdom as this history may appear, you will scarcely deem the next I have to relate less singular and less worthy of admiration. That ants should have their milch cattle is as extraordinary as that they should have slaves. Here, perhaps, you may again feel a fit of incredulity shake you;—but the evidence for the fact I am now stating being abundant and satisfactory, I flatter myself it will not shake you long.

The loves of the ants and the aphides (for these last are the kine in question) have long been celebrated; and that there is a connexion between them you may at any time, in the proper season, convince yourself; for you will always find the former very busy on those trees and plants on which the latter abound: and if you examine more closely, you will discover that their object in thus attending upon them is to obtain the saccharine fluid, which may well be denominated their milk[88], that they secrete.

This fluid, which is scarcely inferior to honey in sweetness, issues in limpid drops from the abdomen of these insects, not only by the ordinary passage, but also by two setiform tubes placed, one on each side, just above it. Their sucker being inserted in the tender bark, is without intermission employed in absorbing the sap, which, after it has passed through the system, they keep continually discharging by these organs. When no ants attend them, by a certain jerk of the body, which takes place at regular intervals, they ejaculate it to a distance: but when the ants are at hand, watching the moment when the aphides emit their fluid, they seize and suck it down immediately. This, however, is the least of their talents; for they absolutely possess the art of making them yield it at their pleasure; or, in other words, of milking them. On this occasion their antennæ are their fingers; with these they pat the abdomen of the aphis on each side alternately, moving them very briskly; a little drop of fluid immediately appears, which the ant takes into its mouth, one species (Myrmica rubra) conducting it with its antennæ, which are somewhat swelled at the end. When it has thus milked one, it proceeds to another, and so on, till being satiated it returns to the nest.

Not only the aphides yield this repast to the ants, but also the Cocci, with whom they have recourse to similar manœuvres, and with equal success; only in this case the movement of the antennæ over their body may be compared to the thrill of the finger over the keys of a piano-forte.

But you are not arrived at the most singular part of this history,—that ants make a property of these cows, for the possession of which they contend with great earnestness, and use every means to keep them to themselves. Sometimes they seem to claim a right to the aphides that inhabit the branches of a tree or the stalks of a plant; and if stranger-ants attempt to share their treasure with them, they endeavour to drive them away, and may be seen running about in a great bustle, and exhibiting every symptom of inquietude and anger. Sometimes, to rescue them from their rivals, they take their aphides in their mouth, they generally keep guard round them, and when the branch is conveniently situated, they have recourse to an expedient still more effectual to keep off interlopers,—they inclose it in a tube of earth or other materials, and thus confine them in a kind of paddock near their nest, and often communicating with it.

The greatest cow-keeper of all the ants, is one to be met with in most of our pastures, residing in hemispherical formicaries, which are sometimes of considerable diameter. I mean the yellow ant of Gould (F. flava). This species, which is not fond of roaming from home, and likes to have all its conveniences within reach, usually collects in its nest a large herd of a kind of Aphis, that derives its nutriment from the roots of grass and other plants (Aphis radicum); these it transports from the neighbouring roots, probably by subterranean galleries, excavated for the purpose, leading from the nest in all directions[89]; and thus, without going out, it has always at hand a copious supply of food. These creatures share its care and solicitude equally with its own offspring. To the eggs it pays particular attention, moistening them with its tongue, carrying them in its mouth with the utmost tenderness, and giving them the advantage of the sun. This last fact I state from my own observation; for once upon opening one of these ant-hills early in the spring, on a sunny day, I observed a parcel of these eggs, which I knew by their black colour, very near the surface of the nest. My attack put the ants into a great ferment, and they immediately began to carry these interesting objects down into the interior of the nest. It is of great consequence to them to forward the hatching of these eggs as much as possible, in order to ensure an early source of food for their colony; and they had doubtless in this instance brought them up to the warmest part of their dwelling with this view. M. Huber, in a nest of the same ant, at the foot of an oak, once found the eggs of Aphis Quercûs.

Our yellow ants are equally careful of their Aphides after they are hatched, when their nest is disturbed conveying them into the interior, fighting fiercely for them if the inhabitants of neighbouring formicaries, as is sometimes the case, attempt to make them their prey; and carrying them about in their mouths to change their pasture, or for some other purpose. When you consider that from them they receive almost the whole nutriment both of themselves and larvæ, you will not wonder at their anxiety about them, since the wealth and prosperity of the community is in proportion to the number of their cattle. Several other species keep Aphides in their nests, but none in such numbers as those of which I am speaking[90].

When the population exceeds the produce of a country, or its inhabitants suffer oppression, or are not comfortable in it, emigrations frequently take place, and colonies issue forth to settle in other parts of the globe; and sometimes whole nations leave their own country, either driven to this step by their enemies, or excited by cupidity to take possession of what appears to them a more desirable residence. These motives operate strongly on some insects of the social tribes.—Bees and ants are particularly influenced by them. The former, confined in a narrow hive, when their society becomes too numerous to be contained conveniently in it, must necessarily send forth the redundant part of their population to seek for new quarters; and the latter—though they usually can enlarge their dwelling to any dimensions which their numbers may require, and therefore do not send forth colonies, unless we may distinguish by that name the departure of the males and females from the nest—are often disgusted with their present habitation, and seek to establish themselves in a new one:—either the near neighbourhood of enemies of their own species; annoyance from frequent attacks of man or other animals; their exposure to cold or wet from the removal of some species of shelter; or the discovery of a station better circumstanced or more abundant in aphides;—all these may operate as inducements to them to change their residence. That this is the case might be inferred from the circumstance noticed by Gould[91], which I have also partly witnessed myself, that they sometimes transport their young brood to a considerable distance from their home. But M. Huber, by his interesting observations, has placed this fact beyond all controversy; and his history of their emigrations is enlivened by some traits so singular, that I am impatient to relate them to you. They concern chiefly the great hill-ant (F. rufa), though several other species occasionally emigrate.

Some of the neuters having found a spot which they judge convenient for a new habitation, apparently without consulting the rest of the society, determine upon an emigration, and thus they compass their intention: The first step is to raise recruits:—with this view they eagerly accost several fellow citizens of their own order, caress them with their antennæ, lead them by their mandibles, and evidently appear to propose the journey to them. If they seem disposed to accompany them, the recruiting officer, for so he may be called, prepares to carry off his recruit, who, suspending himself upon his mandibles, hangs coiled up spirally under his neck;—all this passes in an amicable manner after mutual salutations. Sometimes, however, the recruiter takes the other by surprise, and drags him from the ant-hill without giving him time to consider or resist. When arrived at the proposed habitation, the suspended ant uncoils itself, and, quitting its conductor, becomes a recruiter in its turn. The pair return to the old nest, and each carries off a fresh recruit, which being arrived at the spot joins in the undertaking:—thus the number of recruiters keeps progressively increasing, till the path between the new and the old city is full of goers and comers, each of the former laden with a recruit. What a singular and amusing scene is then exhibited of the little people thus employed! When an emigration of a rufescent colony is going forward, the negroes are seen carrying their masters: and the contrast of the red with the black renders it peculiarly striking. The little turf-ants (Myrmica? cæspitum) upon these occasions carry their recruits uncoiled, with their head downwards and their body in the air.

This extraordinary scene continues several days; but when all the neuters are acquainted with the road to the new city, the recruiting ceases. As soon as a sufficient number of apartments to contain them are prepared, the young brood, with the males and females, are conveyed thither, and the whole business is concluded. When the spot thus selected for their residence is at a considerable distance from the old nest, the ants construct some intermediate receptacles, resembling small ant-hills, consisting of a cavity filled with fragments of straw and other materials, in which they form several cells; and here at first they deposit their recruits, males, females, and brood, which they afterwards conduct to the final settlement. These intermediate stations sometimes become permanent nests, which however maintain a connexion with the capital city[92].

While the recruiting is proceeding it appears to occasion no sensation in the original nest; all goes on in it as usual, and the ants that are not yet recruited pursue their ordinary occupations: whence it is evident that the change of station is not an enterprise undertaken by the whole community. Sometimes many neuters set about this business at the same time, which gives a short existence (for in the end they all reunite into one) to many separate formicaries. If the ants dislike their new city, they quit it for a third, and even for a fourth: and what is remarkable, they will sometimes return to their original one before they are entirely settled in the new station; when the recruiting goes in opposite directions, and the pairs pass each other on the road. You may stop the emigration for the present, if you can arrest the first recruiter, and take away his recruit[93].

I shall now relate to you some other portions of Myrmidonian History, which, though perhaps not so striking and wonderful as the preceding details, are not devoid of interest, and will serve to exemplify their incredible diligence, labour, and ingenuity.

In this country it is commonly in March, earlier or later according to the season, that ants first make their appearance, and they continue their labours till the middle or latter end of October. They emerge usually from their subterranean winter-quarters on some sunny day; when, assembling in crowds on the surface of the formicary, they may be observed in continual motion, walking incessantly over it and one another, without departing from home; as if their object, before they resumed their employments, was to habituate themselves to the action of the air and sun[94]. This preparation requires a few days, and then the business of the year commences. The earliest employment of ants is most probably to repair the injuries which their habitation has received during their state of inactivity: this observation more particularly applies to the hill-ant (F. rufa), all the upper stories of whose dwellings are generally laid flat by the winter rains and snow; but every species, it may well be supposed, has at this season some deranged apartments to restore to order, or some demolished ones to rebuild.

After their annual labours are begun, few are ignorant how incessantly ants are engaged in building or repairing their habitations, in collecting provisions, and in the care of their young brood; but scarcely any are aware of the extent to which their activity is carried, and that their labours are going on even in the night.—Yet this is a certain fact.—Long ago Aristotle affirmed that ants worked in the night when the moon was at the full[95]; and their historian Gould observes, "that they even exceed the painful industrious bees. For the ants employ each moment, by day and night, almost without intermission, unless hindered by excessive rains[96]." M. Huber also, speaking of a mason-ant, not found with us, tells us that they work after sun-set, and in the night[97]. To these I can add some observations of my own, which fully confirm these accounts. My first were made at nine o'clock at night, when I found the inhabitants of a nest of the red ant (Myrmica rubra) very busily employed; I repeated the observation, which I could conveniently do, the nest being in my garden, at various times from that hour till twelve, and always found some going and coming, even while a heavy rain was falling. Having in the day noticed some Aphides upon a thistle, I examined it again in the night, at about eleven o'clock, and found my ants busy milking their cows, which did not for the sake of repose intermit their suction. At the same hour, another night, I observed the little negro ant (F. fusca) engaged in the same employment upon an elder. About two miles from my residence was a nest of Gould's hill-ant (F. rufa), which, according to M. Huber, shut their gates, or rather barricade them, every night, and remain at home[98]. Being desirous of ascertaining the accuracy of his statement, early in October, about two o'clock one morning, I visited this nest in company with an intelligent friend; and to our surprise and admiration we found our ants at work, some being engaged in carrying their usual burthen, sticks and straws, into their habitation, others going out from it, and several were climbing the neighbouring oaks, doubtless to milk their Aphides. The number of comers and goers at that hour, however, was nothing compared with the myriads that may always be seen on these nests during the day. It so happened that our visit was paid while the moon was near the full; so that whether this species is equally vigilant and active in the absence of that luminary yet remains uncertain. Perhaps this circumstance might reconcile Huber's observation with ours, and confirm the accuracy of Aristotle's statement before quoted. To the red ant, indeed, it is perfectly indifferent whether the moon shine or not; they are always busy, though not in such numbers as during the day. It is probable that these creatures take their repose at all hours indifferently; for it cannot be supposed that they are employed day and night without rest.

I have related to you in this and former letters most of the works and employments of ants, but as yet I have given you no account of their roads and track-ways.—Don't be alarmed, and imagine I am going to repeat to you the fable of the ancients, that they wear a path in the stones[99]; for I suppose you will scarcely be brought to believe that, as Hannibal cut a way for the passage of his army over the Alps by means of vinegar, so the ants may with equal effect employ the formic acid: but more species than one do really form roads which lead from their formicaries into the adjoining country. Gould, speaking of his jet-ant (F. fuliginosa), says that they make several main track-ways, (streets he calls them,) with smaller paths striking off from them, extending sometimes to the distance of forty feet from their nest, and leading to those spots in which they collect their provisions; that upon these roads they always travel, and are very careful to remove from them bits of sticks, straw, or anything that may impede their progress; nay, that they even keep low the herbs and grass which grow in them, by constantly biting them off[100], so that they may be said to mow their walks. But the best constructors of roads are the hill-ants (F. rufa). Of these De Geer says, "When you keep yourself still, without making any noise, in the woods peopled with these ants, you may hear them very distinctly walking over the dry leaves which are dispersed upon the soil, the claws of their feet producing a slight sound when they lay hold of them. They make in the ground broad paths, well beaten, which may be readily distinguished, and which are formed by the going and coming of innumerable ants, whose custom it is always to travel in the same route[101]." From Huber we further learn, that these roads of the hill-ants are sometimes a hundred feet in length, and several inches wide; and that they are not formed merely by the tread of these creatures, but hollowed out by their labour[102]. Virgil alludes to their tracks in the following animated lines, which, though not altogether correct, are very beautiful:

Bonnet, observing that ants always keep the same track both in going from and returning to their nest, imagines that their paths are imbued with the strong scent of the formic acid, which serves to direct them; but, as Huber remarks, though this may be of some use to them, their other senses must be equally employed, since it is evident, when they have made any discovery of agreeable food, that they possess the means of directing their companions to it, though it is scarcely possible that the path can have been sufficiently impregnated with the acid for them to trace their way to it by scent. Indeed the recruiting system described above, proves that it requires some pains to instruct ants in the way from an old to a new nest; whereas, were they directed by scent, after a sufficient number had passed to and fro to imbue the path with the acid, there would be no occasion for further deportations[103].

Though ants have no mechanical inventions to diminish the quantum of labour, yet by numbers, strength, and perseverance they effect what at first sight seems quite beyond their powers. Their strength is wonderful: I once, as I formerly observed, saw two or three of them haling along a young snake not dead, which was of the thickness of a goose-quill[104]. St. Pierre relates, that he was highly amused with seeing a number of ants carrying off a Patagonian centipede. They had seized it by all its legs, and bore it along as workmen do a large piece of timber[105]. The Mahometans hold, as Thevenot relates, that one of the animals in Paradise is Solomon's ant, which, when all creatures in obedience to him brought him presents, dragged before him a locust, and was therefore preferred before all others, because it had brought a creature so much bigger than itself. They sometimes, indeed, aim at things beyond their strength; but if they make their attack, they pertinaciously persist in it though at the expense of their lives. I have in my cabinet a specimen of Colliuris longicollis, Latr., to one of the legs of which a small ant, scarcely a thirtieth part of its bulk, is fixed by its jaws. It had probably the audacity to attack this giant, compared with itself, and obstinately refusing to let go its hold was starved to death[106]. Professor Afzelius once related to me some particulars with respect to a species of ant in Sierra Leone, which proves the same point. He says that they march in columns that exceed all powers of numeration, and always pursue a straight course, from which nothing can cause them to deviate: if they come to a house or other building, they storm or undermine it; if a river comes across them, though millions perish in the attempt, they endeavour to swim over it.

This quality of perseverance in ants on one occasion led to very important results, which affected a large portion of this habitable globe; for the celebrated conqueror Timour, being once forced to take shelter from his enemies in a ruined building, where he sat alone many hours, desirous of diverting his mind from his hopeless condition, he fixed his observation upon an ant that was carrying a grain of corn (probably a pupa) larger than itself up a high wall. Numbering the efforts that it made to accomplish this object, he found that the grain fell sixty-nine times to the ground, but the seventieth time it reached the top of the wall. "This sight (said Timour) gave me courage at the moment; and I have never forgotten the lesson it conveyed[107]."

Madame Merian, in her Surinam Insects, speaking of the large-headed ant (Œcodoma cephalotes), affirms that, if they wish to emigrate, they will construct a living bridge in this manner:—One individual first fixes itself to a piece of wood by means of its jaws, and remains stationary; with this a second connects itself; a third takes hold of the second, and a fourth of the third, and so on, till a long connected line is formed fastened at one extremity, which floats exposed to the wind, till the other end is blown over so as to fix itself to the opposite side of the stream, when the rest of the colony pass over upon it, as a bridge[108]. This is the process, as far as I can collect it from her imperfect account:—as she is not always very correct in her statements, I regarded this as altogether fabulous, till I met with the following history of a similar proceeding in De Azara, which induces me to give more credit to it.

He tells us, that in low districts in South America, that are exposed to inundations, conical hills of earth may be observed, about three feet high, and very near to each other, which are inhabited by a little black ant. When an inundation takes place, they are heaped together out of the nest into a circular mass, about a foot in diameter and four fingers in depth. Thus they remain floating upon the water while the inundation continues. One of the sides of the mass which they form is attached to some sprig of grass, or piece of wood; and when the waters are retired, they return to their habitation. When they wish to pass from one plant to another, they may often be seen formed into a bridge, of two palms length, and of the breadth of a finger, which has no other support than that of its two extremities. One would suppose that their own weight would sink them; but it is certain that the masses remain floating during the inundation, which lasts some days[109].

You must now be fully satiated with this account of the constant fatigue and labour to which our little pismires are doomed by the law of their nature; I shall therefore endeavour to relieve your mind by introducing you to a more quiet scene, and exhibit them to you during their intervals of repose and relaxation.

Gould tells us that the hill-ant is very fond of basking in the sun, and that on a fine serene morning you may see them conglomerated like bees on the surface of their nest, from whence, on the least disturbance, they will disappear in an instant[110]. M. Huber also observes, after their labours are finished, that they stretch themselves in the sun, where they lie heaped one upon another, and seem to enjoy a short interval of repose: and in the interior of an artificial nest, in which he had confined some of this species, where he saw many employed in various ways, he noticed some reposing which appeared to be asleep[111].

But they have not only their time for repose; they also devote some to relaxation, during which they amuse themselves with sports and games. "You may frequently perceive one of these ants (F. rufa) (says our Gould) run to and fro with a fellow-labourer in his forceps, of the same species and colony. It appeared first in the light of provisions; but I was soon undeceived by observing, that after being carried for some time, it was let go in a friendly manner, and received no personal injury. This amusement, or whatever title you please to give it, is often repeated, particularly amongst the hill-ants, who are very fond of this sportive exercise[112]." A nest of ants which Bonnet found in the head of a teazle, when enjoying the full sun, which seems the acme of formic felicity, amused themselves with carrying each other on their backs, the rider holding with his mandibles the neck of his horse, and embracing it closely with his legs[113]. But the most circumstantial account of their sports is given by Huber. "I approached one day," says he, "one of their formicaries (he is speaking of F. rufa) exposed to the sun and sheltered from the north. The ants were heaped together in great numbers, and seemed to enjoy the temperature which they experienced at the surface of the nest. None of them were working: this multitude of accumulated insects exhibited the appearance of a boiling fluid, upon which at first the eye could scarce fix itself without difficulty. But when I set myself to follow each ant separately, I saw them approach each other, moving their antennæ with astonishing rapidity; with their fore-feet they patted lightly the cheeks of other ants: after these first gestures, which resembled caresses, they reared upon their hind-legs by pairs, they wrestled together, they seized one another by a mandible, by a leg or an antenna, they then let go their hold to renew the attack; they fixed themselves to each other's trunk or abdomen, they embraced, they turned each other over, or lifted each other up by turns—they soon quitted the ants they had seized, and endeavoured to catch others: I have seen some who engaged in these exercises with such eagerness, as to pursue successively several workers; and the combat did not terminate till the least animated, having thrown his antagonist, accomplished his escape by concealing himself in some gallery[114]." He compares these sports to the gambols of two puppies, and tells us that he not only often observed them in this nest, but also in his artificial one.

I shall here copy for you a memorandum I formerly made. "On the ninth of May, at half-past two, as I was walking on the Plumstead road near Norwich, on a sunny bank I observed a large number of ants (Formica fusca) agglomerated in crowds near the entrances of their nest. They seemed to make no long excursions, as if intent upon enjoying the sun-shine at home; but all the while they were coursing about, and appeared to accost each other with their antennæ. Examining them very attentively, I at length saw one dragging another, which it absolutely lifted up by its antennæ, and carrying it in the air. I followed it with my eye, till it concealed itself and its antagonist in the nest. I soon noticed another that had recourse to the same manœuvres; but in this instance the ant that was attacked resisted manfully, a third sometimes appearing inclined to interfere: the result was, that this also was dragged in. A third was haled in by its legs, and a fourth by its mandibles. What was the precise object of these proceedings, whether sport or violence, I could not ascertain. I walked the same way on the following morning, but at an earlier hour, when only a few comers and goers were to be seen near the nest:" And soon leaving the place, I had no further opportunity to attend to them.

And now having conducted you through every apartment of the formicary, and shown you its inhabitants in every light, I shall leave you to meditate on the extraordinary instincts with which their Creator has gifted them, reserving what I have to say on the other social insects for a future occasion.

I am, &c.