When they discover a wasp’s nest, they attack the papery covering to get at the larvae pupae and newly-hatched wasps. In spite of the rage of the parents, who vainly keep flying about them, they carry off their spoil in fragments; the carriers having their loads apportioned to their size—the dwarfs taking the smaller pieces, and the stronger fellows the heavier portions. Sometimes two ants join in carrying one piece.
Robber Ecitons.
Another species (the Eciton legionis) has been known to attack other ants’ nests for the sake of plunder. Mr Bates saw an army of them employed on the face of an inclined bank of earth. They were excavating mines to get at the nest of a larger species of ant of the genus Formica. Some were rushing into the passages, others were seen assisting their comrades to lift out the bodies of the formicae, while others were tearing them in pieces—their weight being too great for that of a single eciton. A number of carriers then seized each a fragment and carried it down the slope. When the naturalist dug into the earth with a small trowel, the eager freebooters rushed in as fast as he excavated, and carried off the ants, so rapidly tearing them in pieces that he had great difficulty in rescuing a few entire specimens.
The little ecitons seemed to be divided into parties, some excavating, others carrying away the grains of earth. When the shafts became rather deep, the mining parties had to climb up the sides each time they wished to cast out a pellet of earth; but their work was lightened by their comrades, who stationed themselves at the mouth of the shaft and relieved them of their burdens, carrying the particles to a sufficient distance from the edge of the hole to prevent them rolling in again. All the work seemed thus to be performed by intelligent co-operation among the host of eager little creatures. Still, there was not a rigid division of labour; for some of them, whose proceedings he watched, acted at one time as carriers of pellets, and at another as miners, and all shortly afterwards assumed the office of conveyers of the spoil. In about two hours, all the nests of the formicae were rifled.
He frequently saw these little creatures engaged apparently in play, in the neighbourhood of their homes. Some were walking slowly about, others were brushing their antennae with their fore-feet; but the drollest sight was to see them cleaning one another. Here and there an ant was seen stretching forth first one leg, then another, to be brushed or washed by one or more of its comrades; who performed the task by passing the limb between the jaw and the tongue, finishing by giving the antennae a friendly wipe.
There are two species of blind ecitons—which, however, go on foraging expeditions, and even attack the nests of other stinging species; but, avoiding the light, they move always under leaves and fallen branches: when the columns have to pass a cleared space, the ants form covered ways with granules of earth, arched over and holding together mechanically.
Blind Ants.
Two other species—Eciton vastator, and Eciton erratica—both of which are blind, move entirely under covered ways in search of promising hunting-grounds. Their arcades are sometimes two hundred yards in length, the grains of earth being taken from the soil over which the column is passing, and fitted together without cement. In this they are distinguished from the covered ways made by the termites, who use a glutinous saliva for cementing their edifices. These blind ecitons build up the side of their convex arcade, and in a wonderful manner contrive so to fit in the key-stones, without allowing the loose uncemented structure to fall to pieces. Whenever a breach is made in any of their covered ways, the workers remain behind to repair the damage, while the soldiers issue forth in a menacing manner, rearing their heads, and snapping their jaws with an expression of fiercest rage and defiance.
The above account will give some idea of the vast numbers and varieties of the termites and ants of this region, and of the wonderful way in which Providence has furnished them with the means of sustaining existence, and taking their part in the economy of nature. Science is deeply indebted to Mr Bates, for his persevering efforts and acute observation in making known the varieties and habits of these curious insects.