Remarkable Habits of Ants
By A. Hyatt Verrill
Of all the lower animals none are more interesting, more worthy of study or possessed of greater “intelligence” than the ants. Many of their actions seem as if inspired by reason, and surely in their social life they have improved upon mankind. Even our commonest species have remarkable habits when we come to observe and study them more closely.
One of their most common habits is that of keeping "aphids" or plant lice, in place of cows. The ants not only secure food in the shape of a sweet substance known as "honey-dew" from their tiny cattle, but feed and care for them as well, even building little sheds over their herds to protect them from rain. If the plant on which the aphids are feeding dies or becomes poor pasturage, the ants carry their cattle to better feeding grounds.
When cold weather approaches they carry the eggs and pupae of the plant-lice to their own nests, and care for them tenderly throughout the winter, and, when the eggs hatch in spring, place the young on healthy plants where they will be sure to have abundant food. The aphids are not the only insects cared for, however, some species of leaf-hoppers, those droll "Brownies of the insect world," are treated in much the same manner.
Several kinds of beetles, spiders and wasps live within the dwellings of the ants in perfect harmony with the rightful owners. Some of these guests undoubtedly render their hosts valuable services for their board, but others prey regularly upon the young ants, and it is a mystery yet unsolved why they should be permitted to remain unmolested. The larvae of some of these guests closely resemble the young ants, while others are very unlike them, and require quite a different sort of food. When one of these larva considers it meal time he strokes the face of an ant in a very comical manner, and the ant immediately obliges it with a drop of honey-like fluid, on its lower lip, which is eagerly devoured by the beetle.
Many of our large red ants are slaveholders and curiously enough the slaves are almost always black! When a colony of ants desire slaves a regular army is formed, skirmishers are thrown out and scouts sent ahead to discover a nest of black ants and look over the ground. The invading army is composed entirely of warrior ants, with powerful jaws, quite different from the common workers. When the nest of the intended victims is reached a fierce battle takes place and many are killed and wounded on both sides. The more powerful invaders are always victorious, however, and entering the nest of the vanquished they rob it of the eggs and pupae, which they carry to their own home. The returning victors are welcomed on their arrival with various manifestations of joy, and the young of their defeated foe taken within and carefully tended until they reach maturity. Strangely enough the slaves thus obtained are willing and obliging bondsmen, doing all the harder work of the community and even feeding their captors. Indeed, some species of slave-holding ants are incapable of feeding themselves, and, if it were not for their slaves, would die of starvation in the midst of plenty.
Although our northern ants are so interesting, it is in the warmer portions of the world that their most remarkable habits are shown. In Texas the "agricultural ant" raises regular crops of certain species of grass, the seeds of which they harvest and store in well constructed granaries. Their little farms are very carefully tended, all weeds and encroaching plants carefully destroyed and the soil kept loose and manured.
The "army ants" of tropical America are remarkable mainly for the immense numbers in which they travel from place to place, devouring every particle of animal food in their path. Sometimes in the course of their marches they enter houses, and, although the occupants are obliged to vacate for the time being, they welcome the visit of the ants, as upon their departure they are sure to leave the dwelling free from roaches, rats, mice and all other vermin. Apparently these army ants do not possess the sense of smell, for walking-leaves and walking-sticks frequently save their lives by remaining motionless when overtaken by the army, the ants even passing over them, evidently unaware of the food hidden by the semblance of leaf or twig.
A relative of the army ant and found in the same localities is known as the "Leaf-carrier." These little fellows march along in single file, each one carrying a triangular piece of green leaf above his head. The pieces of leaf are used in building their home and cultivating a sort of fungus used as food, and only one kind of leaf is used apparently. Frequently the ants are obliged to travel several miles in order to secure the leaves, and the endless procession of moving bits of green, winding up hill and down dale along a well-worn path, presents a curious appearance
Ants have many kinds of nests, some in the earth, some in wood, others in trees or bushes, and still others between leaves. The most curious ants' nest in the world, however, is found in Java, and is known as the "ant-plant," from the fact that its large woody root is almost invariably inhabited by a certain species of ant. The curious part of it, however, is that the chambers, galleries and tunnels are not made by the ants who live therein, but naturally formed, ready for the tenants.
The most wonderful habit recorded of any ant, however, is beyond doubt that of an Asiatic species which lives in nests constructed of leaves fastened together with silk. Whereas the adult ants have no means of spinning this silk themselves, their young possess a small quantity which they use in forming cocoons within which they change to pupae. Their parents avail themselves of this in a manner so remarkable as to be scarcely credible. While several individuals hold the edges of two leaves together, another member of the colony grasps a larva in his jaws and rubs its mouth along the seam, when the young immediately excretes its silk in a sticky fluid state. As soon as the supply of one larva is exhausted, another is brought, and the operation repealed until the seams are all safely and strongly glued together by the aid of this living mucilage.