The Ants
These little creatures are probably the most intelligent of all the insects—and yet at times they seem to wander about almost aimlessly. A worker may be found with an insect or something which it is eagerly dragging along and drops probably from fear. It appears anxious to regain its hold of it, but goes about in all sorts of wrong directions before it again finds it, it may be to make sure its enemy is clear away before it resumes operations, but the effect to the ordinary onlooker is one of sheer incapacity—at the same time the wonderful habits of the tribe, the way in which they keep plant lice for their larvæ, their methods of carrying each other, their nest-building, and the slave-making instincts of some of the species, show an intelligence surpassed by no other family of insects. Their nests are formed in very various ways: the same species even will sometimes nest under a stone and sometimes make ant hills; some of the large species make their nests of huge heaps of fir needles, and number 400 to 500 thousand in one nest—others live in quite small communities, nesting in bramble stems, old rotten wood, moss, etc. One little species, rare with us, lives in the walls of other ants’ nests, just as mice live in the walls of our houses; another quite small species lives apparently on friendly terms with the common large red or horse ant, and may be found running about amongst them, on and in their nests, but, so far as I know, nothing is known as to how its young are reared. There is a curious division in the family between the ants that have true stings and those which have not. The large ants of our fir woods can bite and are able to eject poison through the apical opening of the body into the wound they create, but these as well as the larger and smaller black ants and some others have the sting undeveloped, whereas some of our small species have a sting which they can use with considerable effect; this difference in habit is accompanied by a difference in the structure in the basal segments of the body. In the stingless species the basal segment is reduced to a flat upright transverse scale (fig. 6, 1); in the stinging ants two segments at the base are reduced to nodes (fig. 6, 3). There is an exception in the case of one little rare genus, Ponera, which has only the basal abdominal segment reduced to a scale although a much thicker scale than in the others (fig. 6, 2), and yet which has a distinct sting. These arrangements give the body very free movement so that the tail can be bent forward till it reaches the head. Another curious distinction between the stingers and non-stingers is that the larvæ of the former spin cocoons and those of the latter do not; the larvæ of Formica fusca occasionally do not do so, but they are an exception to the rule. Cocoon spinning seems to involve the larvæ in some difficulties, as without the help of the worker ants they are often unable to extract themselves from their prison. This is a condition which does not, I believe, exist in other groups. In the stingless ants there is a curious difference in habit between the species of the genus Formica, where, according to Forel, the workers do not follow in line over unknown ground, and frequently carry one another, the one carried being rolled up under the head of the other, and the species of Lasius, where the workers follow one another in line, but never carry each other. Among the stinging ants another method of carrying occurs in certain genera. The porter seizes the one she wishes to carry by the external edge of one of her mandibles and then throws her over her back, so that she lies along the back of her porter with her ventral aspect uppermost and her legs and antennæ folded as in the nymph state. Neither of these methods sounds very comfortable, but then probably an ant’s idea of comfort and our own may be very different.
Lord Avebury, in his Ants, Bees and Wasps, tells us that he has known a male of Myrmica ruginodis live for nine months, although no doubt, as he says, they generally die almost immediately, and he has known queen ants to live for seven years, and workers, which he had in his nest, for six years.