The seeds, when thus brought into the nest, are stored by the ants in long galleries, or in vaulted chambers, the floors of which have been specially prepared for its reception. It is a very curious thing that the stored seeds, though they often become quite moist, do not germinate, as would be the case under ordinary circumstances, if we, for instance, were to lay them in some cave or cellar. Were they to do so they would become bitter, and, of course, unfit for food, so that it seems as if the ants must have some way of stopping the process of nature. What this way is we do not know, but if, out of a great many thousands, some of the seeds do begin to sprout, the ants bite off the little rootlet or radicle that then makes its appearance, by which act the germination is prevented from going farther. It is quite as wonderful that the ants should have found out how to prevent the seeds from growing in their nests—and do it in two ways—as it is that they should plant it in fields specially prepared for it to grow upon.
CHAPTER IX
ANT ARMIES—A SNAKE’S PRECAUTION—WONDERFUL BRIDGES AND TUNNELS—MUSHROOM-GROWING ANTS.
We will next consider the foraging ants of such tropical countries as Brazil and Western Equatorial Africa. To the latter the name of driver-ants has been given, because when they set out on their invading marches they drive every living thing, including man, before them. Everything they seize they devour, and as they go in great numbers and constantly open out into two or more columns so as to enclose patches of the forest, hosts of creatures find it impossible to escape destruction. Du Chaillu gives an interesting account of these ants, which were called bashikonay by the natives amongst whom he was living. He says: “This ant is very abundant in the whole region I have travelled over in Africa, and is the most voracious creature I ever met. It is the dread of all living animals from the leopard to the smallest insect. I do not think they build a nest or house of any kind. At any rate, they carry nothing away, but eat all their prey on the spot. It is their habit to march through the forests in a long regular line—a line about two inches broad, and often several miles in length. All along this line are larger ants, who act as officers, stand outside the ranks, and keep this singular army in order. If they come to a place where there are no trees to shelter them from the sun, whose heat they cannot bear, they immediately build underground tunnels, through which the whole army passes in columns, to the forest beyond. These tunnels are four or five feet underground, and are used only in the heat of the day, or during a storm. When they grow hungry, the long file spreads itself through the forest in a front line, and attacks and devours all it overtakes with a fury which is quite irresistible. The elephant and gorilla fly before this attack. The black men run for their lives. Every animal that lives in their line of march is chased. They seem to understand, and act upon, the tactics of Napoleon, and concentrate, with great speed, their heaviest forces upon the point of attack. In an incredibly short space of time the mouse, or dog, or leopard, or deer is overwhelmed, killed, eaten, and the bare skeleton only remains.”
These terrible insects travel night and day. “Many a time,” says Du Chaillu, “have I been awakened out of a sleep and obliged to rush from the hut and into the water, to save my life, and after all, suffered intolerable agony from the bites of the advance-guard, who had got into my clothes. When they enter a house they clear it of all living things. Cockroaches are devoured in an instant. Rats and mice spring round the room in vain. An overwhelming force of ants kills a strong rat in less than a minute, in spite of the most frantic struggles, and in less than another minute its bones are stripped. Every living thing in the house is devoured. When on their march the insect-world flies before them, and I have often had the approach of a bashikonay army heralded to me by this means. Wherever they go they make a clean sweep, even ascending to the tops of the highest trees in pursuit of their prey. Their manner of attack is an impetuous leap. Instantly the strong pincers are fastened and they only let go when the piece gives way. At such times this little animal seems animated by a kind of fury which causes it to disregard entirely its own safety, and to seek only the conquest of its prey. The bite is very painful.” This latter statement it is easy to believe from the figure given in Du Chaillu’s book of one of these driver, or bashikonay ants. It is drawn twice the size of the real insect, but, even so, this would make the latter at least as large as a wasp. The head is enormous, larger than the thorax and abdomen—which make the body—together, and from it a huge pair of curved and pointed mandibles project and cross each other at the tips. When fairly covered with such creatures the effect would be that of thousands of tiny pincers, all tearing out pieces of flesh at the same time. No wonder that the negroes who are naked, or nearly so, run for their lives. In old times, Du Chaillu tells us, native criminals used to be tied down in the path of these terrible ants, to be torn to pieces and devoured by them—a shocking piece of cruelty which one is glad to know even then (more than forty years ago) and amongst savages, was a thing of the past. This terrible fate, however, must sometimes overtake those who are too old or ailing to escape by their own efforts, and to assist whom there is no time, and possibly but little inclination.
But in spite of such catastrophes, and of the danger and inconvenience which these driver-ants cause to the negroes, they are yet, in reality, very useful to them, since, several times a year, their huts are freed from the vermin with which they at all times abound.
If the gorilla and elephant fly before these ants, one can understand that snakes, however large, would also be afraid of them; and accordingly we have a curious story told by the natives, of the anxiety felt by the great python lest he should be overtaken by their armies, whilst lying torpid after a meal, and of the means which he takes to avoid such a catastrophe. Having killed his prey by crushing it in the great folds of his body, he leaves it lying on the ground, and does not return until, having made a circle of a mile or more in diameter, about the body, he is assured that no ant-army is on the march. Only then does he dare to swallow his prey and risk the dangerous period of sluggish inactivity which is necessitated by the process of digestion. If, however, the object of fear should be met with the python glides off with all possible speed, leaving the booty to be devoured by the ants should they happen to come upon it.
The habit of these driver-ants of making a tunnel as they march along, and thus sheltering themselves from the heat of the sun, is very remarkable, but I cannot quite understand how they drive it so deep under the ground as Du Chaillu says. To do so must surely delay them for a very long time, and the quicker and more expedient course would seem to be to wait for the sun to go down, and then to cross the open space. However, we should never assume, in natural history, that a certain course will be pursued by any animal, simply because it is the best one. Often, however obvious this seems, they act otherwise. From other accounts, however, it would seem as if the ants threw up their tunnel on the surface of the ground instead of excavating beneath it, and that, sometimes, the structure reared by them is more of the nature of an awning than a tunnel. The Rev. Dr. Savage, for instance, says: “If they should be detained abroad till late in the morning of a sunny day, by the quantity of their prey, they will construct arches over their path, of dirt agglutinated by a fluid excreted from their mouth. If their way should run under thick grass, sticks, etc., affording sufficient shelter, the arch is dispensed with; if not, so much dirt is added as is necessary to eke out the arch, in connexion with them.”