Homes Without Hands: Being a Description of the Habitations of Animals, Classed According to Their Principle of Construction
One of the large workers is now before me, and a most formidable insect it looks. Its head is round, smooth, and very large, and is armed with a pair of enormous forceps, curved almost as sharply as the horns of the chamois, and very sharp at the points. Their length is so great that, if straightened and placed end to end, they would be longer than the head and body together. They are beset with minute hairs, which, when viewed under the microscope, are seen to be stiff bristles, arranged in regular rings round the mandibles. The thorax and abdomen are but slender; the limbs are long, giving evidence of great activity. In the dried specimen, the color of the insect is yellowish-brown, becoming paler on the head; but when the creature is alive, the head is nearly white. The eyes are very minute, looking like little round dots on the side of the head, and being so extremely small that they can scarcely be perceived without the aid of a magnifying-glass. The half-inch power of the microscope shows that they are oval and convex, but as they are set in little pits or depressions, they do not project beyond the head. The hexagonal compound lenses, which are generally found in insects, are not visible, and the eye bears a great resemblance to that of the spider.
The difference in dimensions of the workers is very remarkable. The specimen which I have just described measures a little under half an inch in length, exclusive of the limbs, while another specimen is barely half that length, and in general appearance much resembles the familiar ant, or emmet of our gardens.
The presence of these insects may be always known by the numbers of pittas, or ant-thrushes, which feed much upon them, and which are sure to accompany a column of Foraging Ants on the march. The ant-thrushes are odd, short-tailed birds, with stout bodies, and a remarkably long hind claw. Some of this species are decorated with colors of wonderful brilliancy, glittering with blue, green, copper-red, and purple, and having a peculiar silken gloss. Others are soberly clad in simple brown and white, and such are the birds which usually accompany the Foraging Ants on their march.
As soon as the experienced inhabitants of tropical America see the ant-thrushes, they rejoice in the coming deliverance, and welcome the approaching army. The fact is, that in those countries insect life swarms as luxuriously as the vegetation, and there are many insects which, however useful in their own place, are apt to get into houses, and there multiply to such an extent that they become a real plague, and nearly drive the inhabitants out of their own homes. They are bad enough by day, but at night they issue from the nooks and crevices where they lay concealed, and make their presence too painfully known.
There are insects that bite, and insects that suck, and insects that scratch, and insects that sting, and many are remarkable for giving out a most horrible odor. Some of them are cased in armor as hard as crab-shells, and will endure almost any amount of violence, while some are as round, as plump, as thin-skinned, and as juicy as over-ripe gooseberries, and collapse almost with a touch. There are great flying insects which always make for the light, and, unless it is defended by glass, will either put it out, or will singe their wings and spin about on the table in a manner that is by no means agreeable. The smaller insects get into the inkstand and fill it with their tiny carcasses, while others run over the paper and smear every letter as it is made. There are great centipedes, which are a legitimate cause of dread, being armed with poison-fangs scarcely less venomous than those of the viper. There are always plenty of scorpions; while the chief army is composed of Cockroaches, of dimensions, appetite, and odor such as we can hardly conceive in this favored land. As to the lizards, snakes, and other reptiles, they are so common as almost to escape attention.
For a time these usurpers reign supreme. Now and then a few dozen are destroyed in a raid, or a person of sanguine temperament amuses his leisure hours and improves his marksmanship by picking off the more prominent intruders with a saloon pistol; but the vacancies are soon filled up, and no permanent benefit is obtained. But when the Foraging Ants make their appearance, the case is altered, for there is nothing that withstands their assault. As soon as the pittas are seen approaching, the inhabitants throw open every box and drawer in the house, so as to allow the ants access into every crevice, and then retire from the premises.
Presently the vanguard of the column approaches, a few scouts precede the general body, and seem to inspect the premises, and ascertain whether they are worth a search. The long column then pours in, and is soon dispersed over the house. The scene that then ensues is described as most singular. The ants penetrate into the corners, peer into each crevice, and speedily haul out any unfortunate creature that is lurking therein. Great cockroaches are dragged unwillingly away, being pulled in front by four or five ants, and pushed from behind by as many more. The rats and mice speedily succumb to the onslaught of their myriad foes, the snakes and lizards fare no better, and even the formidable weapons of the scorpion and centipede are overcome by their pertinacious foes.
In a wonderfully short time the Foraging Ants have completed their work, the scene of turmoil gradually ceases, the scattered parties again form into line, and the procession moves out of the house, carrying its spoils in triumph. The raid is most complete; and when the inhabitants return to the house, they find every intruder gone, and, to their great comfort, are enabled to move about without treading on some unpleasant creature, and to put on their shoes without previously knocking them against the floor for the purpose of shaking out the scorpions and similar visitors.
In the illustration a column of Foraging Ants is seen winding its way through a wood. Every one who is accustomed to the country takes particular care not to cross one of these columns. The Foraging Ants are tetchy creatures, and, not having the least notion of fear, are terrible enemies even to human beings. If a man should happen to cross a column, the ants immediately dash at him, running up his legs, biting fiercely with their powerful jaws, and injecting poison into the wound. The only plan of action in such a case is to run away at top speed until the main body are too far off to renew the attack, and then to destroy the ants that are already in action. This is no easy task, for the fierce little insects drive their hooked mandibles so deeply into the flesh that they are generally removed piecemeal, the head retaining its hold after the body has been pulled away, and the mandibles clasped so tightly that they must be pinched from the head and detached separately.
There seems to be scarcely a creature that these insects will not attack, and they will even go out of their way to fall upon the nests of the large and formidable wasps of that country. For the thousand stings the ants care not a jot, but tear away the substance of their nest with their powerful jaws, penetrate into the interior, break down the cells, and drag out the helpless young. Should they meet an adult wasp, they fall upon it, and cut it to pieces in a moment.
Another species, Eciton predator, does not form long and narrow columns, but marches in a broad and solid phalanx. It is but a little creature, no bigger than the common red ant of England. It is, however, of a brighter red color, and when a phalanx of these ants ascends a tree, the vast multitudes spread over all the trunk and branches in such numbers that the tree looks as if a blood-red liquid was being poured over it.
There is another Foraging Ant which forms in broad columns when on the march. This is Eciton legionis, a species which is not so common as either of the preceding, and appears only to be seen on the wide sand-plains of Santarem.
These insects sometimes attack the nest of one of the large burrowing ants. Mr. Bates mentions that on one occasion he watched a large army of Foragers begin their attack upon the nest of an ant, some specimens of which he desired to procure. The Foragers set to work with wonderful skill, arranging themselves into two distinct sets of laborers, one set digging into the ground and taking out large pellets of earth, and the other set receiving them from their comrades and carrying them away.
While watching the proceedings of the soldiers when repairing the Thames river-wall after the terrible explosion near Belvedere, I was strongly reminded of the Foraging Ants and their method of working. The parallel was exact in every respect. The officers stood here and there and directed the efforts of their men, while the workers were arranged in regular lines, one set of men digging out the clods of earth, and a second set receiving them and handing them to the spot where they were wanted. I could but fancy that if an observer had been poised at some height above the beach in a balloon, and watched the soldiers at work, and had previously seen an army of Ecitons engaged in sinking a shaft, he would have seen the insects and their labors precisely reproduced in the human beings, art having at last discovered a process which was in full operation before man knew how to handle a weapon or a tool.
After Mr. Bates had watched the proceedings of the ants for some time, he took a trowel and opened the ground with it. The clever insects at once took advantage of this aid, and dashed into the breach by thousands, pouncing on the luckless inhabitants and carrying them off in their jaws. So bold and so quick were they, that Mr. Bates could scarcely manage to secure a single specimen; and even when he had caught an ant, the Foragers would pull it out of his fingers.
The same observer has known them to sink their shafts to a depth of ten inches, invariably succeeding in their raid upon the nest. The materials of which the nest is made they pull to pieces, and carry the fragments home, together with the inmates. When the nest is completely sacked, the invaders move out in small lines, which march to join the main body, and soon unite with it. The discipline of the community is really wonderful.
Each insect knows its own place and its own work, and so perfect is the organization, that during the busy season the long train resolves itself into two distinct columns, one going out to search for food, and the other returning home laden with spoil.
Another species, Eciton rapax, is also in the habit of attacking the nest of various ants. In habits it is very similar to the preceding insect, and is chiefly remarkable for being the largest of all the Ecitons, the average length being half an inch.
The last species of Eciton which I shall mention is that wonderful species which is called the BLIND ANT (Eciton erratica).
I have already mentioned that in Eciton drepanophora the eyes are very small, but in the Blind Ant they are absolutely wanting, the horny covering of the head being quite uniform, without the least trace of external eyes. Some naturalists have thought that the Blind Ant may possess organs of vision, and that the horny covering of the head is sufficiently transparent to admit the light. That the insects can distinguish light from darkness is perfectly true, for they display the greatest uneasiness when brought into the light, and therefore it is possible that the optic nerves may be in some degree affected, though there are no external organs of vision. But the covering of the head is certainly too thick and too opaque to permit distinct vision, and that the insect can see an object clearly is manifestly impossible.