The entomologist who would make a study of ant-life could find no better school to pursue it in than the grand valley of the Amazon. In all parts of it he will find these insects in countless numbers, and in a vast variety of species,—separated from each other by all distinctions of classes founded on habits of life quite opposed to each other. Some species inhabit the earth, never descending below its surface. Others live under it, in subterranean dwellings, scarce ever coming out into the light of day. Others again live above the earth, making their home in the hollow trunks of trees; while still others lead a more aerial life, building their nests among the twigs and topmost branches.
In their diet there is a still greater range. There are carnivora and herbivora,—some that feed only on flesh, others that confine themselves to vegetable substances. There are, moreover, kinds that devour their meat before the life is out of it; while other carnivorous species, like the vulture among birds, prey only on such carrion as may chance to fall in their way, and in search of which their lives seem principally to be spent.
Then there are the vegetable feeders, which not only strip the leaves from plants and trees, but destroy every other sort of vegetable substance that they may fancy to seize upon. The clothes in a chest or wardrobe, the papers in a desk, and the books in a library, have all at times been consumed by their devastating hosts, when foraging for food, or for materials out of which to construct their singular dwellings. These dwellings are of as many different kinds as there are species of ants. Some are of conical shape, as large as a soldier’s tent. Some resemble hillocks or great mounds, extending over the ground to a circumference of many yards. Others represent oblong ridges, traversed by numerous underground galleries, while some species make their dwellings in deep horizontal tunnels, or excavations, often extending under the bed of broad rivers. Many kinds lead an arboreal life, and their nests may be seen sticking like huge excrescences to the trunks of the forest-trees, and as often suspended from the branches.
To give a detailed account of the different kinds of Amazonian ants,—to describe only their appearance and ordinary habits,—would require, not a chapter, but a large volume. Their domestic economy, the modes of constructing their domiciles, the manner of propagating their species, their social distinction into classes or castes, the odd relations that exists between the separate castes of a community, the division of labour, their devotion to what some writers, imbued with monarchical ideas, have been pleased to term their queen,—who in reality is an individual elected for a special purpose, render these insects almost an anomaly in nature. It is not to be expected that the uneducated Indian could give any scientific explanation of such matters. He only knew that there were many curious things in connection with the ants, and their indoor as well as out-door life, which he had himself observed,—and these particulars he communicated.
He could tell strange tales of the Termites, or white ants, which are not ants at all,—only so called from a general resemblance to the latter in many of their habits. He dwelt longest on the sort called Saübas, or leaf-carrying ants, of which he knew a great number of species, each building its hill in a different manner from the others. Of all the species of South American ants, perhaps none surprises the stranger so much as the saüba. On entering a tract of forest, or passing a patch of cultivated ground, the traveller will come to a place where the whole surface is strewn with pieces of green leaves, each about the size of a dime, and all in motion. On examining these leafy fragments more closely, he will discover that each is borne upon the shoulders of a little insect not nearly so big as its burden. Proceeding onward he will come to a tree, where thousands of these insects are at work cutting the leaves into pieces of the proper size, and flinging them down to thousands of others, who seize upon and carry them off. On still closer scrutiny, he will observe that all this work is being carried on in systematic order,—that there are some of the insects differently shaped from the rest,—some performing the actual labour, while the others are acting as guards and overseers. Were he to continue his observation, he would find that the leaves thus transported were not used as food, but only as thatch for covering the galleries and passages through which these countless multitudes make their way from one place to another. He would observe, moreover, so many singular habits and manoeuvres of the little crawling creatures, that he would depart from the spot filled with surprise, and unable to explain more than a tenth part of what he had seen.
Continuing his excursion, he would come upon ants differing from the saübas not only in species, but in the most essential characteristics of life. There would be the Ecitons, or foraging ants, which instead of contenting themselves by feeding upon the luxurious vegetation of the tropics, would be met upon one of their predatory forays,—the object of their expedition being to destroy some colony of their own kind, if not of their own species. It may be that the foraging party belong to the species known as Eciton-rapax,—the giant of its genus, in which many individuals measure a full half-inch in length. If so, they will be proceeding in single file through the forest, in search of the nests of a defenceless vegetable-feeding ant of the genus Formica. If they have already found it, and are met on their homeward march towards their own encampment, each will be seen holding in its mouth a portion of the mangled remains of some victim of their rapacity.
Again, another species may be met travelling in broad columns, containing millions of individuals, either on the way to kill and plunder, or returning laden with the spoil. In either case they will attack any creature that chances in their way,—man himself as readily as the most defenceless animal. The Indian who encounters them retreats upon his tracks, crying out, “Tauóca!” to warn his companions behind, himself warned by the ant-thrushes whom he has espied hovering above the creeping columns, and twittering their exulting notes, as at intervals they swoop down to thin the moving legion.
Of all the kinds of ants known to the Mundurucú, there was none that seemed to interest him more than that which had led to the conversation,—the tocandeira, or, as the Brazilians term it, formigade fogo (fire-ant). Munday had worn the formidable mittens; and this circumstance had no doubt left an impression upon his mind that the tocandeira was the truest representative of spitefulness to be found in the insect world.
Perhaps he was not far astray. Although an ant of ordinary size,—both in this and general appearance not differing greatly from the common red ant of England,—its bite and sting together are more dreaded than those of any other species. It crawls upon the limbs of the pedestrian who passes near its haunt, and, clutching his skin in its sharp pincer-like jaws, with a sudden twitch of the tail it inserts its venomous sting upon the instant, holding on after it has made the wound, and so tenaciously that it is often torn to pieces while being detached. It will even go out of its way to attack any one standing near. And at certain landing-places upon some of the Amazonian rivers, the ground is so occupied with its hosts that treading there is attended with great danger. In fact, it is on record that settlements have been abandoned on account of the fire-ant suddenly making its appearance, and becoming the pest of the place.
Munday, in conclusion, declared that the tocandeiras were only found in the dry forests and sandy campos; that he had never before seen one of their swarms in the Gapo, and that these in the dead-wood must have retreated thither in haste, to escape drowning when caught by the inundation, and that the log had been afterwards drifted away by the echente.