Page:Popular Science Monthly Volume 7.djvu/278

264 class; the large-heads have, in some species, greatly-lengthened jaws; the small-heads have jaws always of the ordinary shape, but the two classes are not sharply defined in structure and function, except in two species. In these the jaws of the worker-majors are so monstrously lengthened that they are incapacitated for taking part in the labors of the worker-minors, and act as soldiers. The peculiar feature in the habits of the genus Eciton is their hunting for prey in regular bodies or armies. It is this which chiefly distinguishes them from the genus Myrmica, the common red stinging-ant of the temperate zone, whose habit is to search for food in the usual irregular manner. All the Ecitons hunt in large organized bodies; but almost every species has its own special manner of hunting.

—In this species there is no division in classes among its workers, although the difference in size is very great. It lives in open places, and its movements are easy to be observed; its sting and bite are not very formidable. The armies consist of thousands of individuals, and move in rather broad columns. They are quick to break line on being disturbed, and attack hurriedly and furiously any intruding object. Their activity seems to be chiefly directed to plundering the nests of a large defenseless ant of another genus (Formica).

—This, one of the commonest species of foraging-ants, confines its ravages to the thickest part of the forest. When a pedestrian falls in with one of their trains, the first signal given him is a twittering and restless movement of small flocks of plain-colored birds (ant-thrushes) in the jungle. If this be disregarded, and he advances a few steps farther, he is sure to fall into trouble, and find himself suddenly attacked by numbers of the ferocious little creatures. They swarm up his legs with incredible rapidity, each one driving his pincer-like jaws into his skin, and, with the purchase thus obtained, doubling its tail and stinging with all its might. There is no course left but to run for it. The tenacious insects then have to be plucked off, one by one, a task which is generally not accomplished without pulling them in twain, and leaving heads and jaws sticking in the wounds.

The errand of the vast ant-armies is plunder. Wherever they move, the whole animal world is set in commotion, and every creature tries to get out of their way. It is especially wingless insects that have cause to fear, such as heavy-bodied spiders, maggots, caterpillars, larvæ of cockroaches, etc., all of which live under fallen leaves, or in decaying wood. The main column, from four to six deep, moves forward in a given direction, clearing the ground of all animal matter, dead or alive, and throwing out here and there a thinner column to forage for a short time on the flanks of the main army. If some rich place be encountered, for example, a mass of rotten wood abounding in insect-larvæ, a delay takes place, and a very strong force is