The history of a tribe of insects so long celebrated for their industry and frugality, and for the display of that sagacity which characterizes some of the higher orders of animals, is peculiarly calculated to occupy the attention of modern naturalists. The ancients, indeed, had often noticed the habits and economy of the ant; but their accounts, at all times deficient in accuracy from the want of precise definitions and logical arrangement of the objects they describe, are in this instance so mixed up with fanciful notions and chimerical doctrines, and so coloured by the vivid imagination and credulity of the narrators, as to have retarded rather than advanced the progress of real knowledge. Aristotle and Pliny report, for instance, that the labours of ants are in a great measure regulated by the phases of the moon; and the latter mentions a species found in the northern parts of India, whose size was said to equal that of the wolves of Egypt, whose colour was the same as that of a cat, and whose occupation in winter consisted in digging up gold from the bowels of the earth; while the inhabitants in the summer robbed them of their treasures, after having decoyed them, by stratagem, from their nests. Great mistakes have prevailed, even in later times, from the circumstance of the larvae of ants bearing a resemblance to grains of corn, which it was supposed these insects hoarded up as a provision for winter consumption. The form of the eggs and of the larvae, and the attention paid to them by the ants, were described by Dr King in the 23d number of the Philosophical Transactions; but Leuwenhoek was the first who distinguished with precision the different forms which the insect assumes in the several stages of its growth. He traced the successive changes from the egg to the larva, the nymph, and the perfect insect. Swammerdam pursued his scrutiny into these successive developments with greater minuteness; and, unrivalled in the art of microscopic dissection, discovered the wonderful encasement of all the parts of the future ant at every preceding stage, and showed that it appears under such different forms only from the nature of its envelopes, each of which, at the proper period, is in its turn cast off. Linnæus (Memoirs of the Royal Academy of Sciences at Stockholm, vol. ii.) ascertained some of the leading facts with regard to the distinction between the sexes, and determined that the ants which are furnished with wings are the only individuals that exercise the sexual functions. Several particulars with regard to the economy of the ants were published by Mr Gould, in a book entitled An Account of English Ants, of which an abstract is given in the Philosophical Transactions for 1747, by the Rev. Dr Miles. The facts are there stated with tolerable correctness; but some errors have been committed by following too closely the analogy with bees. Geoffroy (Histoire des Insectes qui se trouvent aux Environs de Paris), though a good naturalist on other topics, is a bad authority on the subject of ants. The most complete series of observations on the natural history of these insects, is that for which we are indebted to the celebrated Swedish entomologist De Geer (Mémoires pour servir à l'Histoire des Insectes), an observer on whose fidelity the most implicit reliance may be placed.

In the Encyclopédie Méthodique, under the article Fourmi, Olivier has drawn up an able statement of all the material facts that had been established by preceding naturalists; without, however, adding any original observations of his own, excepting the description of five or six undescribed species. A full account of the habits of those ants which for a long period infested the island of Martinique, is contained in some of the earlier numbers of the Journal de Physique (vols. ix. and x.). The author of these memoirs, M. Barboteau, has given many curious details on this subject, and has cited a number of facts on various authorities; and the account might now be swollen by the reports of subsequent travellers in different parts of the world; but these statements are often made upon slender authority, and are too much tinctured with the marvellous to admit of much credit being attached to them. The narrative given to us by Bonnet in the second volume of his Observations sur les Insectes, of the proceedings of a colony of ants which had established itself in the head of a large thistle, and which he transported into his house, is highly interesting; but it elucidates only a few points of their economy, and leaves us to regret that so patient and indefatigable an observer had not bestowed more of his attention to the study of this tribe of insects. In the Philosophical Transactions for 1790 we find an interesting memoir on the sugar-ant, a species which, for a period of ten years, committed dreadful ravages in the sugar plantations throughout the whole island of Grenada. The most methodical account of this tribe of insects that has yet appeared is that of Latreille, in his Histoire Naturelle des Fourmis, published at Paris in 1802, a work which alone would have secured the reputation of the author as an able and scientific naturalist. His merit is particularly conspicuous in the clearness and accuracy of his descriptions of each species, and the luminous method of arrangement which he has adopted in their classification. He gives an account of one hundred species which he had himself observed, and of twenty-four which he has described from the reports of others; these he distributes into nine natural families, according to the situation and structure of the antennæ, and the form of the abdominal scales. But the work which contains the most copious collection of facts relative to the habits and economy of ants is that of Mr P. Huber of Geneva, entitled Traité des Mœurs des Fourmis Indigènes, published in 1816. By means of an apparatus which he contrived so as to admit of his obtaining a view whenever he pleased of the inmost recesses of their habitation, he was enabled to observe what was going on in the interior of the nest, and to investigate with success some of the most important and interesting features of their history. The results of his researches, as they are reported in his work, are highly curious and instructive, and open a wide field of speculation and inquiry to the philosophical entomologist. They have not only elucidated many obscure points with regard to one tribe of insects, but have disclosed some general views of the instincts and faculties of this order of the creation, which are totally new, and must tend, in a considerable degree, to exalt our conceptions of the inexhaustible powers and resources of nature.

Having thus pointed out the principal sources of information in this department of entomology, we shall proceed to give an outline of the leading facts that have been ascertained relative to the economy and domestic policy of these remarkable insects.

In common with many tribes of hymenopterous insects, Functions ants present the remarkable peculiarity of a threefold disjunction of sex among the individuals of the same species; a circumstance which is met with in no other order of the animal kingdom, and which appears, as far as observation has extended, to be totally excluded from the plan of the vegetable creation. Besides males and females, there exists an apparently intermediate order of neuters, which are also denominated labouring or working ants. The neuters, thus exempted from every sexual function, exercise, on the other hand, all the other offices necessary for the existence and welfare of the community to which they belong. It is they who collect supplies of food, who explore the country for this purpose, and seize upon every animal substance, whether living or dead, which they can lay hold of; and transport to their nest. It is they who construct every part of their dwelling-place, who attend to the hatching of the eggs, to the feeding of the larva, and to their removal, as occasion may require, to different situations favourable to their growth and development; and who, both as aggressors and as defenders, fight all the battles of the commonwealth, and provide for the safety of their weaker and more passive companions. Thus all the laborious and perilous duties of the state are performed solely by this description of ants, who act the part of helots in these singularly constituted republics of insects. We find, however, on closer examination, that, in all probability, this anomaly in point of sex is more apparent than real; and that, however different in external conformation from the productive females, they nevertheless originally and essentially belong to the same sex. There is every reason to believe that the development of the sexual organs in the former is the consequence of some difference in the circumstances in which the larva is placed during its growth. That such is the case with bees, is now perfectly well established; and the analogy of bees with ants, in many points of physiology, must be admitted as a strong argument in corroboration of this theory. In all the essential features of internal structure, the supposed neuters agree with the female, and differ from the male of the same species. In all hymenopterous insects, which are armed with stings, a difference exists in the two sexes, as to the number of articulations composing the antennae; those of the female consisting of fewer pieces than those of the male. The accurate observations of Mr Kirby (Monographia Apum) have determined that in the bee the antennae of the male have fifteen articulations, while those of the female and the neuter have only fourteen. In the ant, likewise, we find thirteen articulations in the male, and only twelve in the female; and likewise only twelve in the neuter. In the male ant the abdomen has seven rings, in the female and neuter only six. In the two latter classes the head is broader, and the mandibles very large and powerful compared with those of the male, and are furnished with serrated edges, and a sharp and often hooked point. The external sexual organs of the female and of the neuter are so nearly similar in appearance, that Latreille declares he was unable to perceive the least difference between them. On the other hand, it is to be observed, that in the neuter the principal deviation from the model of the female consists in the absence of wings; a circumstance which, as it regards the organs of locomotion only, is one of subordinate importance in the economy; and their presence may, without difficulty, be conceived to be connected with a certain condition of the sexual organs, as are the horns of the deer, and the beard in the human species. But although of so little consequence in a physiological point of view, it is a circumstance materially affecting their external condition. It dooms them to severe toil and exertion in traversing the ground, and in climbing up the steep paths that may lie in their route; while their more luxuriant and favoured associates are fluttering in the spacious realms of air in search of amusement, and waited to the objects of their gratification on the light breezes of the summer.

Ants appear to be endowed with a greater share of muscular strength than almost any other insect of the same size. Of this we have sufficient proofs in the vivacity of their movements, the incessant toil which they undergo, the great loads which they are seen to carry, often exceeding ten or twelve times their own weight, and the agility which they exert in making their escape from danger. This high degree of irritability is conjoined, apparently, with a corresponding share of the power of sensation; a power which is manifested in their susceptibility to a variety of impressions capable of affecting the organs of sense. They have a quick perception of all changes of temperature, as well as of other conditions of the atmosphere; and are readily and disagreeably affected by moisture. In the perfection of the sense of sight, they seem to be nearly on a level with other insects; and the males and females are provided with both the descriptions of eyes peculiar to this class, namely, the composite and the simple eyes. The labouring ants, indeed, who never fly, are frequently destitute of the latter kind; a circumstance which appears to confirm the suspicion that has often been entertained, that the simple eyes are chiefly instrumental in the vision of distant objects. Latreille describes two species of ants, in which he could not discover the least appearance whatsoever of eyes, although he employed a high magnifying power in examining them. One of these (the Formica cecus) is a foreign species, inhabiting the forests of Guiana, and of which the history is therefore little known. The other (the Formica contracta) is met with in the vicinity of Paris. It always conceals itself during the day under stones, or in obscure recesses, where no light can penetrate; and emerges from its retreat only during the night. It is much less social in its habits than other ants, collecting in groups only of about a dozen individuals, and appears to be far inferior in sagacity to the rest of the tribe.

Ants possess a considerable acuteness of smell, a sense which appears to be useful not only in directing them to their food, but also, as Bonnet first remarked, in enabling them to follow by the scent the track of their companions. If the end of the finger be passed two or three times across the line of their march, so as to brush off the odorous particles with which the ants who had already passed that way may have impregnated the track, those who follow immediately stop on arriving at the place where the experiment has been made, and afterwards direct their course irregularly, till they have passed over the space touched by the finger, when they soon find the path, and proceed with the same confidence as before. Bonnet repeated this experiment frequently, and always with the same result. Latreille has endeavoured to discover the seat of smell, which had long been suspected to reside in the antennae. He, with this view, deprived several labouring ants of these organs, and replaced them near their nests. When thus mutilated, they wandered to and fro in all directions, as if they were delirious, and utterly unconscious of where they were going. Some of their companions were seen to notice their distress, and, approaching them with apparent compassion, applied their tongues to the bleeding wounds of the sufferers, and anointed them with a liquor which they caused to flow from their own mouths. This trait of sensibility was repeatedly witnessed by Latreille, while he was observing their actions with a magnifying lens.

It is indeed evident that, in all insects, the antennae are organs of the greatest utility in conveying impressions from external objects. But in the ant, independently of their importance as organs of touch, they appear to be of still greater consequence to the welfare of the individual, and of the community to which it belongs, by being the chief instruments which enable them to communicate to one another intelligence in which they are mutually interested, and on which they are called upon immediately to act. Mr Huber, to whom we are indebted for a variety of curious observations on this subject, has given the name of Language Antennal to this species of intercourse. The situation of the antennae, which are placed in front of the head, their great mobility, their peculiar mechanism, which presents a series of phalanges having great freedom of play, and endowed with exquisite sensibility, conspire to fit them admirably for the function which he assigns to them,—that of producing a variety of different impressions, when applied in different ways to the antennae or other parts of those ants with which they come in contact. Thus the signal of danger, which consists in the ant which gives the alarm striking its head against the corset of the other, is propagated from ant to ant with astonishing quickness, throughout the whole society. For a few minutes a general ferment prevails, as if they were deliberating what measures to pursue; but their resolution is soon formed, and they are ready to rush in a body against the enemy. Any small animal that is discovered to have insolently invaded their repose is certain of falling a victim to their resentment, unless he can make a precipitate retreat, which he seldom effects without being covered with the bites of these furious insects. They are not, however, equally jealous of the intrusion of every kind of insect, for woodlice are often found in the interior of the nest, to whom, according to Latreille, they offer no molestation. Ants appear to be incapable of emitting sounds, so as to communicate with one another at a distance; and there is, indeed, no evidence that they possess the sense of hearing. The consideration of the sense of taste naturally comprehends that of their food, to which we shall therefore next proceed.

Very erroneous opinions were prevalent with regard to the food of ants, which have often been supposed to consume corn, and to do great injury to plants by devouring their roots or stems. The truth is, that they are chiefly carnivorous insects, preying indiscriminately on all the softer parts of animals, and especially the viscera of other insects. These, indeed, they will often attack when alive, and overpower by dint of numbers; either devouring their victim on the spot, or dragging it a prisoner into the interior of the nest. If, however, the game should be too bulky to be easily transported, they make a plentiful meal, and exert, like the bee, a power of disgorging a portion, and of imparting it to their companions at home; and it appears that they are even able to retain at pleasure the nutritious juices unchanged for a considerable time. The rapidity with which they consume, and in fact atomize, the carcass of any small bird or quadruped that happens to fall in their way, is well known, and furnishes an easy method of obtaining natural skeletons of these animals, by placing their dead bodies in the vicinity of a populous ant-hill. In hot climates, where they multiply to an amazing extent, their voracity and boldness increase with their numbers. Bosman, in his description of Guinea, states that, in one night, they will devour a sheep, leaving it a fine skeleton; while a fowl is for them only the amusement of an hour. In these situations they will venture to attack even living animals of considerable size. Rats and mice often become their victims. The sugarants of Grenada cleared every plantation which they visited of rats and other vermin, which they probably effected by attacking their young. Poultry, or other small stock, could not be raised without the greatest difficulty; and the eyes, nose, and other emunctories of the bodies of dying or dead animals, were instantly covered with them. They generally, indeed, begin their attacks on the most sensible parts, which have the finest cuticle; and, accumulating in great numbers about the nostrils, destroy the animal by interrupting respiration. Negroes with sores had difficulty in keeping the ants from assailing them. Their power of destruction keeping pace with their increase of numbers, it is hardly possible to assign limits to either; and the united hosts of this diminutive insect have often become formidable to man himself. A story is related by Prévost, in his Histoire Générale des Voyages, of an Italian missionary, resident in Congo, who was awakened by his negroes in great alarm at the house being invaded by an immense army of ants, which poured in like a torrent, and before he could rise had already mounted upon his legs. They covered the floor and passages, forming a stratum of considerable depth. Nothing but fire was capable of arresting their progress. He states that cows have been known to be devoured in their stalls by these daring devastators. Smith, in his Voyages to Guinea, reports that at Cape Corse the castle was attacked by legions of ants, who were preceded by thirty or forty, apparently acting as guides. It was at day-break when they made this incursion, entering first by a chapel, on the floor of which some negro servants were lying. Assailed by this new enemy, they fled with precipitation, and gave the alarm to their master, who, on awaking, could hardly recover from his astonishment at beholding the advancing multitude, which extended for a quarter of a mile before him. There was not much time for deliberation; and a happy expedient was adopted of putting a long train of gunpowder across the line of their march, and extending it to their flanks, which had already begun to deploy, and, setting fire to the whole, millions were destroyed at one blow; which so intimidated the rest, that the whole army retreated in disorder, and did not renew the attack.

Descriptions of ant-hills of immense size abound in books of travellers who have visited tropical regions. Mr Campbell (Account of Travels in South Africa, published in 1815) observed in the district of Albany, at the Cape, an ant-hill, five feet high, and twelve in circumference. In the forests of Guiana, according to M. Malonet, they attain the height of from fifteen to twenty feet; and, when viewed from a distance on these widely extended savannas, resemble the rude huts of savages; but they contain a race more ferocious than the savage or the tiger himself, and cannot be approached by men without the utmost danger of being devoured. When new settlers, who are clearing the country, meet with any of these in their progress, they must immediately desist from their task, and even abandon the neighbourhood, unless they can speedily destroy the enemy in the very heart of the citadel which protects him, and from which he is able to pour an overwhelming number of combatants. The only method of accomplishing this is to dig a trench all round the ant-hills, and, after having filled it with dry wood and set fire to it on every side, by lighting it quickly in different places, so as to cut off all retreat to the ants, to batter down the edifice with cannon. The ants, thus scattered, soon perish in the flames.

The chief, if not the only vegetable substance which is at all alluring to their appetite, is sugar. They not only eat it in substance, but are fond of all fluids that contain it in any quantity,—such as the secretions which exude from many trees, and compose what has been termed the honey-dew; and the saccharine juice which is excreted from the bodies of many of the insects belonging to the genus Aphis. This latter species of food they appear to relish above all others: it resembles honey in its qualities, and is sucked with avidity from the insect which yields it, and which appears in no respect to suffer from the operation. Boissier de Sauvages was the first who noticed this singular fact; and Mr P. Huber has ascertained a number of curious circumstances attending it. He conceives that the liquor is given out voluntarily by the aphis, at the solicitation of the ant, who for this purpose strikes it gently and repeatedly with its antennae, using the same motions as it does when caressing its young; and remarks, that the aphis retains this liquor for a longer time, where the ants are not at hand to receive it. A single aphis may often be seen surrounded by three or four ants who are feeding on the honey, and deriving from it a plentiful meal. It does not appear that the aphis uses any exertion to avoid the ants, who are thus dependent on its bounty; for those provided with wings are quite as passive under these circumstances as the rest. They are, however, of an extremely sluggish nature, and may be seen for days on the same stem, in a state of indolent repose, and averse to use their wings.

A singular observation has been recently made by Professor Savi (the younger) of Pisa, in relation to a species of Italian ant, the nest of which is inhabited by a small grasshopper. These animals do not appear to dwell in the same excavations in a merely casual manner, but they are united by some unaccountable bond of union, which renders the society of the one indispensable to the comfort of the other. The association of the ant and the aphis before alluded to is of a dissimilar nature, being the result of force on the one hand, and of necessity on the other. But, as far as it is possible to judge from the observations hitherto recorded, the cohabitation of the ant and the grasshopper is of a more refined and disinterested kind. It is really impossible at present to account for it on any other principle than that of an affectionate interest in each other's society; for no direct advantage appears to result to either party. On this account Signor Savi has named the grasshopper *gryllus myrmecophilus*.1 He proved the friendly alliance which subsists between these species, by watching the migratory and other movements of the ants themselves, during which he discovered that they always carried their little grasshoppers along with them. These latter, during fine weather, are seen to sport and play in the vicinity of the ant-nests, into which they immediately betake themselves during any unfavourable change of the air, or the approach of threatened danger.

The cultivation of the sugar-cane in the West Indian islands has often been severely checked by the ravages of ants; but the injury they occasion arises altogether from their undermining the roots, in order to establish their nests where they can be protected from heavy rains, and secured against agitation from violent winds; advantages which the sugar-cane affords them in a very great degree. No part of the plant constitutes their food; and the same is true of those trees among the roots of which they burrow, and of which they speedily occasion the destruction, by preventing the access of moisture.

Ripe fruits are often attacked by ants, probably on account of the sugar they contain; and, for the same reason, the buds of trees are infested with these insects, and often injured by their depredations. There is no evidence that they at any time feed upon corn or other vegetable seed. This point has been well established by Mr Gould; and Bonnet, who kept a colony of ants prisoners in his study, observed, that, however long they had been kept without food, still they never touched the corn that he put before them. Honey and sweetmeats have strong attractions for ants, who, if they once discover their way to a magazine of these dainties, will immediately communicate the tidings to the rest of the society, and, leading them to the spot, a regular path will soon be established, which will continue to be crowded with a train of depredators so long as anything remains to be pilfered. It is, however, certain, notwithstanding the assertion of Bomare, who compares them to the miser, whose chief pleasure consists in contemplating the riches he has amassed in his coffers, that ants are not in the habit of hoarding provisions for future consumption. They grow torpid when the cold exceeds 27° of Fahrenheit, and in that state require no food; and the aphis affords them sufficient nourishment at other periods of the winter.

In building their nests, each species of ant follows its own peculiar mode of construction, and employs different materials for this purpose. Many form them of clay, and particularly the smaller species; one set building up a regular series of apartments in successive stories, often forty in number, with materials which are furnished to them by another set of workers, who are excavating the ground below. The ceilings are supported throughout by small pillars in some parts, and by vertical walls in others; while broad arches are in other places raised, in order to protect larger spaces, and to admit of lengthened passages of communication throughout a long extent of apartments. These ants can proceed in the building only at such times as the earth has been softened by rain or dew, and the atmosphere is at the same time sufficiently moist to allow of the materials cohering firmly before they dry. Such are probably the ants which Pliny mentions as working by moonlight. On one occasion, when the ants, under the inspection of Mr Huber, had discontinued their labours on account of too great dryness in the atmosphere, he succeeded in getting them to renew their operations by sprinkling water upon them with a wet brush, in imitation of a natural shower. They carefully close the doors of their habitations every night, in order to prevent the intrusion of other insects; and a few remain on the outside during the night as sentinels, to give alarm in case of danger. Some species of ants collect fragments of leaves, of bark, or of straw, with which they construct more permanent and artificially constructed nests than the former. Others employ nothing but the fine powder which they collect from decayed wood. Some, for greater security, establish themselves under a large stone, or in the crevices of decayed buildings. Several tribes, on the other hand, penetrate into the solid substance of wood, which they scoop out into numerous cells, leaving only intermediate partitions of extreme tenuity, just of the strength sufficient to enable the whole fabric to support itself; while it crumbles into powder when pressed between the fingers.

We shall now take a brief review of the principal circumstances relating to the fecundation of the ant, and the evolution and growth of the young. The former is effected very generally during the flight of the females, in which they are accompanied by the males; both appearing to be provided with wings chiefly for this object. A certain number of the females that are impregnated, are also, by the assistance of their wings, enabled to reach distant situations, where they become respectively the founders of new colonies. The males, on the other hand, having fulfilled the office for which nature had destined them, are left to perish on the spot where they descend, being removed from those who formerly administered to them food, and being destitute of the means of procuring subsistence for themselves. Immense swarms of ants are occasionally met with; and some have been recorded of such prodigious density and magnitude as to darken the

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1 Biblioteca Italica, tomo xv. p. 217. air like a thick cloud, and to cover the ground to a considerable extent where they settled. Mr Gleditsch describes, in the History of the Berlin Academy for 1749, shoals of a small black ant which appeared in Germany, and formed high columns in the air, rising to a vast height, and agitated with a curious intestine motion, somewhat resembling the aurora borealis. A similar flight of ants is spoken of by Mr Acolute, a clergyman of Breslaw, which resembled columns of smoke, and which fell on the churches and the tops of the houses, where the ants could be gathered by handfuls. In the German Ephemerides, Dr Charles Rayger gives an account of a large swarm, which passed over the town of Posen, and was directing its course towards the Danube. The whole town was strewed with ants, so that it was impossible to walk without trampling on thirty or forty at every step. And more recently, Mr Dorthes, in the Journal de Physique for 1790, relates the appearance of a similar phenomenon at Montpellier. The shoals moved about in different directions, having a singular intestine motion in each column, and also a general motion of rotation. About sunset they all fell to the ground; and, on examining the ants, they were found to belong to the Formica nigra of Linnæus.

The swarming of ants does not appear to be at all analogous to that of bees: its object seems to be confined to the propagation of the species, and is not the result of any co-operation of numbers, who associate together in search of a new habitation, in which an already populous assemblage may establish themselves. It would appear that the infant colonies consist of very small numbers, and are perhaps wholly the offspring of a common parent, who has migrated alone, or with but a few companions. The greater number of impregnated females alighting in the neighbourhood of the nest, are laid hold of by the labouring ants, who drag them to the nest, where they keep them prisoners till they are ready to deposit their eggs. It is very generally asserted that they also deprive them of their wings; but the later observations of M. Huber disprove that opinion. The impregnated females cast their wings of their own accord. They twist and contort these organs in various directions, till they finally drop off. Such as are unimpregnated have not been observed to perform this singular action. Each female is at this period attended by a numerous retinue of labourers, who treat her with the greatest deference, and are solicitous to anticipate all her wants. Contrary to what happens among bees, many females inhabit the same nest, and live together in the utmost harmony. The eggs, when first deposited, are very small, but become considerably larger before the larva is excluded, being apparently nourished by absorption; for the ants to whose care they are confided are perpetually licking them with their tongues,—a fact which, however curious, is by no means a solitary one in the history of insects. The larva comes forth at the end of a fortnight, and appears in the form of a transparent maggot, with a head and wings, but without any external organs of motion. They are in this state fed by their nurses with a fluid disgorged from their stomachs; and, in the course of their transformation to the state of nymphæ, and of perfect insect, are still dependent upon their assistance. These affectionate guardians help them to extricate themselves from the web of the cocoon, to unfold the duplicatures of their wings, and supply them with food, till they are capable of procuring it for themselves. The young ant is an exceedingly tender and delicate animal, easily destroyed by any considerable variation of temperature, or by excessive humidity; and great care and attention appear to be required to bring it to maturity: it appears to be the constant business of the ants which remain at home to convey them to different parts of the nest, where the temperature is suited to them; and whenever danger threatens they show the utmost solicitude to remove them to situations of security.

Very different degrees of sagacity belong to different tribes of ants. Many traits in the history of the larger gacity kinds, as related by Huber, are of so singular a character as to be scarcely credible if we had received them from a less reputable authority, and if we were not already prepared to admit them, from our knowledge of many equally curious circumstances in the economy of bees, which have been established by the concurrent testimony of the most scrupulous observers. Some tribes of ants, according to this naturalist, who are peculiarly fond of the honey which exudes from the aphis, convey many of these insects into their own nests, lodging them near the vegetables on which they feed, but keeping them prisoners within their habitations, and assigning to them distinct apartments in the subterranean recesses of their dwellings. As if conscious of the future advantages they may derive from these insects, they collect their eggs, and superintend their hatching with the same care which they bestow on the eggs of their own species. The aphis lives in perfect harmony with its keepers, who, so far from molesting it, defend it with courage against ants belonging to other nests, who frequently attempt to get possession of them. Occasionally they are lodged by the ants in fortified buildings, which they construct at a distance from the nest, in situations where they are most secure from invasion. The aphis is not the only genus of insect which furnishes this kind of provision to the ant; the kermes and gall-insect are employed occasionally for the same purpose, and are found domesticated in the nests of ants, at the same time that they contain several species of aphis, and from all of which they collect nutriment.

This picture of domestic harmony is strongly contrasted with the scenes of ferocious contention which are occasionally exhibited between the inhabitants of neighbouring nests; nature appearing to have instilled, together with the love of social order, the same passions of rivalry, of ambition, and of revenge, of which we deplore the operation among beings of a higher order. War, the scourge of the human species, exerts its desolating power among the tribes of gregarious insects, and tends to check their otherwise excessive increase of number. The battles which take place between rival colonies of ants are often on a scale of prodigious magnitude: millions of combatants engage on either side with a fury and pertinacity that is truly astonishing. Their weapons of offence are the jaws, which are capable of inflicting a deep bite, and of instilling into the wound a highly acrid liquor; and also, in many species, a sting resembling in situation and structure that of the bee, and likewise containing a venomous juice. The liquor is well known to possess acid properties, and is now found to consist of two acids, and a volatile one, the formic, of which the constitution is $\text{C}_2\text{H}_2\text{O}_4$. It has been ascertained by the German chemist Döbereiner, that an acid analogous to this animal secretion may be artificially obtained by chemical means. See Chemistry. It is extremely volatile and pungent, and is capable of being thrown out by the ant, when irritated, in considerable quantities. Roux, in the Journal de Médecine for 1762, reports a number of experiments which were made by exposing animals to its influence. Frogs were killed by the vapour from an ant's nest in less than five minutes; and persons breathing it, when of a certain intensity, were nearly suffocated, or were seized with fever, followed by an extensive cutaneous eruption, which terminated in desquamation of the cuticle. Some of the most daring and courageous species, such as that which M. Huber calls the Amazon-ant, make it the business of their lives to attack the nests of the weaker species, and succeed, after a desperate conflict, in plundering them of their eggs and larvae, which they convey to their own nests. These are hatched and reared by ants of the same species as themselves, who may be considered as auxiliaries to the amazons, and who had themselves, at some former period, been kidnapped from their parent nest by the amazons. Thus, a society is formed among different species of insects, to which no parallel exists but in the human race. The amazons live without labour; they are attended, fed, and cherished by the ants which they have procured by this kind of slave-trade, and who take as much care of their offspring as they do of those of their own species. Perfect order is preserved, and the natural instinct of hostility, which in another condition of the society exists between the two tribes, seems in the auxiliaries completely extinguished, by their being educated with the race of their original oppressors.

Ants have numerous enemies among quadrupeds and birds; and some, as the ant-eater, dasypus, and manis or pangolin, together with the tribe of woodpeckers, devour a very large proportion. The Formica leonis, or myrmecion, feeds almost wholly on these insects. The bees at the Cape, according to Mr Campbell, frequently drive out the ants from their nests, of which they take possession themselves. Ants are also infested by lice, which, as may well be imagined, are so minute as to be invisible without the assistance of a very high magnifying power. They are stated by Redi, who discovered them, to resemble in shape those of the fowl and the dove.

The most effectual mode of destroying ants is to pour boiling water into their nests, which destroys at once both the perfect insects and their eggs and larvae; so that those who, being from home, had escaped the general catastrophe, finding it impossible to repair the loss, abandon the spot, and disperse. The addition of urine, or of soot, or still better of tobacco, which may be infused in the water, will render it much more efficacious. A decoction of walnut-leaves or lime-water will also generally answer. The night is the best time for applying these remedies, as the ants are then all collected in the nest. Arsenic is exceedingly destructive to ants, and affords another ready mode of getting rid of those that intrude into cupboards or pantries: it may, for this purpose, be mixed with sugar, or kneaded with any kind of provision, and placed in the paths they are observed to frequent. Corrosive sublimate is also highly poisonous to them, and myriads of the sugar-ants at Grenada were destroyed by means of it; and it is stated to have had the effect of rendering the ants so outrageous that they destroyed each other, as could be seen by a magnifying glass, and even, though less distinctly, by the naked eye. It appears also that this effect was produced even when they only came in contact with the poison. The whole island, however, was so overrun with these ants, that the numbers that could be destroyed by these means bore no sensible proportion to the whole; and recourse was had to fire as more applicable to destruction on a larger scale. It was observed that when wood, burnt to the state of charcoal, without flame, and immediately taken from the fire, was laid in their way, they crowded to it in such amazing numbers as soon to extinguish it, though thousands perished by so doing. Holes were therefore dug at proper distances in a cane-piece, and fire made in each of them. Prodigious quantities perished in this way; for those fires, when extinguished, appeared in the shape of mole-hills, from the numbers of dead that were heaped upon them. But as none of the females or young brood were destroyed by this expedient, the ants soon reappeared in great numbers as before; and the island would probably have continued subject to this scourge, had it not been for the occurrence of the great hurricane of 1780, which at once cleared all the islands of this dreadful pest, by which the sugar-cane plantations had been threatened with total ruin.

For the specific descriptions and systematic arrangement of the different kinds of ants, see Entomology.

Ant-Eater. See Mammalia, Index.

Ant-Hills are little hillocks of earth which the ants throw up for their habitation and the breeding of their young. They are a very great mischief to dry pastures, not only by wasting so much land as they cover, but by hindering the scythe in mowing the grass, and yielding a poor hungry food, pernicious to cattle. The manner of destroying them is to cut them into four parts from the top, and then dig into them so deep as to take out the core below, so that when the turf is laid down again it may lie somewhat lower than the level of the rest of the land. By this means it will be wetter than the rest of the land, and this will prevent the ants from returning to the same place, which otherwise they would certainly do. The earth that is taken out must be scattered to as great a distance every way as may be, otherwise they will collect it together, and make another hill just by. The proper time for doing this is winter; and if the places be left open, the frost and rains of that time of the year will destroy the rest; but in this case care must be taken that they are covered up early enough in the spring, otherwise they will be less fertile in grass than the other places. In Hertfordshire they use a particular kind of spade for this purpose. It is very sharp, and formed at the top into the shape of a crescent, so that the whole edge makes up more than three fourths of a circle; this cuts in every part, and does the business very quickly and effectually. Others use the same instruments that they do for mole-hills. Human dung is a better remedy than all these, as is proved by experiment; for it will kill great numbers of them, and drive all the rest away, if only a small quantity of it be put into their hills.