The Naturalist.

Nelson Evening Mail, Volume XII, Issue 12, 13 January 1877, Page 2

The Naturalist.

«. . OBSERVATIONS ON ANTS. A contribtion to the character and habits of ants has lately been made by a Swiss naturalist, M. Forel. This enquirer establishes the fact, that ants of different varieties make war on each other, the stronger and red kind, known as " For- ' mica sanguinea," overcoming the meadow ; ants, " Formica pratensis," and usually ' reducing them to slavery. The reckless ' fury with which the red ants attack their unfortunate neighbours is described as something dreadful. M. Forel speaks of 1 it as a sort of " drunkenness of fight." * Some of the ants around try to stop these '' delirious combatants by seizing them with ' their feet, and holding 'them till they sober ! down. * On one occasion the author placed a ■ number of workers and cocoons of the ' meadow ant near a residence of red ants ; ' the latter soon carried off the cocoons. ' Was it to eat the pupaa ? By no means. ' Next year presented the curious spectacle ■• of both ants living together in fraternal '' .association. A breach having been made ! in the nest, both kinds carried the cocoons * down below, aud sought to repair the ! disaster with ecpial zeal. Next, a large 1 number of meadow ants were brought j near the habitation, from another district ; but those in the nest, far from welcoming ! them as congeners, fell upon them in con- ' cert with the red ants. The new-comers 1 had the advantage in numbers, and be- ] seiged the nest. The allies, conscious of \ their extremity took to flight, carrying ' away slaves, lame and pupse, and new- j born workers ; and established themselves r at a respectful distance. An alliance has sometimes been effected between the in- ( imical species, which has continued many * years. Very curious is the mixed ant-hill. ' Each species retains its own way of building, so that the architecture is mixed. On • the dome may usually be seen the meadow c ants bearing material, or sunning tbem- | c selves. If you disturb them, or introduce < some unknown animals, they quickly dis- A appear into the nest. They are seeking t assistance. Presently appeals a host of s the -'••Kfc- ants, and if a fight occurs, tbe j meaddw ants do not join in it with th" r others. ■• The newly hatched workers take to '•' domestic work, and do not know friends v from enemies for some time. It seemed ( possible, therefore, to form alliances among 1 several different species, if the subjects 1 brought together were quite young. This ,<

quite tranquilly, the different species all living in concord. In the free state, such associations are impossible ; the only unions realized are between red; and meadow ants. Tho relations betwoen ants of tbe same species, but of different colonies have beenmatter of doubt. The truth is it depends on certain circumstances whether tbey shall be friendly or hostile. Wben the parties are established tolerably separate from each other, under satisfactory conditions, they fight each other " to the bitter" end." If two neighboring ant-hills be i cramped for space, there will be battle and repeated engagements ; but in general, the forces coming to be exhausted, an alliance will at length be formed. If two ant-hills have but a small population, the parties will improve tbeir circumstances by an immediate alliance. When an ant-hill is overcharged with inhabitants, emigrations take place more or less numerous. At the border of a kitchen-garden, a colony of ants had been long established. The paths they took were various ; that most frequented lay across the road, passed into a field, and along the side of a pond to a clump, of trees ; it was very long, in spring a party of ants went to form a colony among the trees: Later, a fiesli party set out from the old home, and became domiciled at the end of another path. The place proved .unsuitable ; they left it and settled on a grass plot a little way off. During the whole summer, the workers of the new establishments often met the workers who still remained in the mother-hill, arid the reception on both sides was evidently cor-, dial. Autumn came, and the meetings were interrupted. Tho following, year, the inhabitants of each nest got into the habit of not moving far from it ; , and the old relations were thus broken off. , After a considerable time had elapsed, the idea occurred to take somo individuals of.the old nest and place them near one of the the young colonies. Received with anything bur. cordiality, they were glad to make their escape. In a second experiment of the same kind, the . new-comers, though less harshly treated were yet received with distrust : It has often been observed that ants separated for a certain time again recognise one another ; but if the separation has been very long, they lose all recollection of their companions. It must be considered, however, that . the population becomes greatly altered by newgenerations. M. Forel made a patient study of the famous amazon ants, which are unabla to construct, or to rear their larva?, or even to eat alone. Their chief, work is fighting ; they cany off the pupue of. working ants in other hills, but afterwards tend these with much care. Many new details are furnished by M. Forel regarding, them. The Amazon ant ("Formica refuseens") is of a pale red, and about six or seven millimetres in length ; the female i.s a little larger. The neuter individual — it can hardly be called a worker — carries five curved aud branched mandibles with drawn-out points. Such an instrument cannot be used to cut wood or temper earth ; it is simply a weapon. , The amazons, thus equipped, fight quite differently from other ants. Unable to seize their adversaries with the legs and cut. off the head or limbs, thy attack the body, or transpierce tbe head with a mandible point. They slioav great agility and impetuosity in their movements, and a courage bordering on rashness. Never seeking safety in flight, the individual will rush on 'a strong ant-hill and kill several of the offenders, till he is overpowered by force of numbers. It is only in desperate cases, however, the amazons show such rashness; when on expeditions, they march in close ranks, retire if serious danger threatens them, and make detours to avoid obstacles. The individual that may have got separated by accident on the way, hastens to rejoin the main body, and he will craftily avoid a too numerous enemy. When the journey is long, the amazons mal* c halts, perhaps for the sake of stragglers, perhaps, also from hesitation as to the direction to be taken. The force ofexpeditionarycolumns is very variable ; sometimes not mure than a few hundred individuals, often from a thousand to two thousand. Thedepartures on these oscasions always take place in the afternoon ; about two o'clock if the temperature is not excessive ; but later, if it is a very hot day. The preparations are speedy. Some ants are seen walking about on the dome in an indifferent way ; suddenly a few individuals go inside ; the signal is given ; the amazons streamforth; they touch each other with the antenna., and the entire company sets off. The slave ants of the colony remain aloof from this movement, and do not appear to give it any attention. Sometimes the amazons go at their object -with surprising certainty ; for example, if they wish to attack a nest, placed on ground which they have been in tbe habit of frequenting. On the other hand, they easily make mistakes when they have to operate on unknown ground ; at times their expeditions are unsuccessful. One day, about 4 p.m., a compact body of amazon ants was observed issuing from their abode (built by the brown ants, their slaves) on a sloping meadow. This troop descends the slope, reaches a vineyard, goes along the border of it a little way, then suddenly stops. The amazons distribute themselves in various directions ; , then, coining forward again, they decide to continue their march forwards. After going a little further, signs of hesitation ' are manifested ; the company again stops, , and scatters itself, one detatebment in one • direction, another in another; but the j search is unavailing. One by one the de- . tachments rejoin the centre of the army ; J then the entire column takes its journey \ homewards, as light as at starting. ' In the , return, when it reaches the slope and begins to ascend, signs of fatigue are ap- . parent, and the march is laborious. Indi- ] viduals at the head of the column come ( back, as if to make sure that none has < fallen out. At length, about 7 p.m., the ( amazons are once more housed. Another ■ 'ime, the band sets out at too late an hour. L'uf ted herbs embarrassing the path allow oi but very slow progress ; the troop changes its mind, and without apparent hesitation, returns to ite nest. It is rare, however, that the amazons illow themselves to be permanently • checked by reverses. M. Forel tolls us of ■ ime case in which a troop came to a field ' af wheat, and after exploring a part of it I without success, the foragers had to re- 1 turn home. Next day, they set out in the < same direction, entered the field, and tra- I versed the whole of it, keeping to tho f right. In coming out, they found them- < ••elves confronted by a large nest of brown ' nits. To invade this by an open gallery l was the work of a moment ; and they soon I came forth again, each amazon with a ( pupaa. The last of them were chased by the brown ants. The robbers resumed < their journey homewards ; but instead of j g^ggn^heirhaWtattOTi^hw^gosit^ i

| they avoided passing too -near, lest they I I might disturh-them in carrying their deus. XThe brown, "ant. that had. beeti. robbed hqd, forseeing a second jaesault, blocked the- openings of the nest with grains of carth — a sorry resource. The amazons ij. the head of the troop waited till the whole body had come up ; then they all rushed upon the hill, broke down tbe barriers, hustled the defenders aside, and loaded themselves with fresh booty. In these expeditions the amazons will sometimes carry off empty shells, carcases, and other useless objects, by mistake. No colony of amazons is complete without a certain number of slaves; and though fqr the most part these consist of the brown ant, the red beard ani (" Formica rufibarbis") is as willingly taken. The latter generally defend themselves with ..the greater energy, but are also always overcome. One afternoon, an immense hord*--* bt^amazons was marching with great assurance in the direction of a large ant-hill. Coming in sight of it, it suddenly stopped, and emissaries rushed along the sides and the rear of the troop, to form the members into a compact mass. The red-beard ants perceived the enemy, and in a few seconds their dome, pierced with holes, was covered witb a host of defenders. The amazons, nothing intimidated, fell on the nest ; the melee was indescribable, but, after a stiff fight, the amazons managed to effect their entrance. Just then, a multitude of red beard ants . were observed coming out with hundreds of larvse and pupae which they wished to save. The besiegers, however, on emerging again, were not without cocoons in their man.dibles; apd having satisfied themselves, . they united in a body, and set off for their habitation. The red-beard ants, now seeing^ them retire, followed in pursuit. : Tlie scene was most curious. One amazon, seized by the legs, would be forced to let golds booty; another, vigorously assaulted, would drop the cocoon he was carrying, to stab the individual who sought to take it. For a long time the red -beard ants thus harassed the amazons ; but the latter, more agile, quickened tbeir pace, and reached their nest with considerable spoil. It would seem as though nothing could discourage the intrepid amazons. Oneday, in frighful weather, a column was observed „on the. march. Passing near a fountain, the. unfortunate creatures were inundated ; but the greater number managed, with much. toil to struggle over the wet grass. Coming to the side of a road, they did, not hesitate to cross, notwithstanding the boisterous wind that was blowing. A little farther on, they succeeded in pillaging an ant-hill. : Returning laden, they struggled along painfully amid the violence of the storm, and were sometimes even swept some distance away. Still, Ihey were never seen to let go their burdens ; and, persevering with indomitable energy, they nearly all succeeded in reaching their destination with the fruits, of their toil. There is a singular kind of ant known as the erratic aut, or the " tapinbme. When menaced, it squirts from the abdomen, a volatile liquid with a very pronounced odour, which suffocates the assailant or puts, him to flight. The tapinomes,change their (subterranean) abodes very frequently, and make the transference with surprising rapidity. They are not of a warlike humour, but defend themselves resolutely if attacked.