But the life of ants is by no means given over to these bucolic pursuits. While the meadow-ants seem to be in the pastoral stage, the red species and the large black ones are hunters and warriors. The most sanguinary conflict I have witnessed was a battle of the ants. Two armies of the same black species met on the floor of a neighbor's barn. The battle lasted throughout several days, and both sides fought with indescribable ferocity. Where they came from was a mystery, as no such colonies of ants had ever been seen thereabouts.
They appeared to be of the species Formica pennsylvanica which nests in trees, but these do not occur in very large colonies, whereas the contending hosts upon the barn floor were as the Tartar hordes. The floor was strewn with struggling pairs and with the dead and injured, and always fresh forces were arriving.
The persistence with which they fought is only to be compared to that of bulldogs, while they showed the ferocity of weasels. Once let an ant get another by the thorax and she would continue crunching and sawing until she had severed the head, notwithstanding in the meantime one or several of her own legs had been cut off by her antagonist. This was the usual outcome of the various individual combats.
From time to time I placed pairs of combatants on the slide of a dissecting lens, and through the glass observed them as in an arena. It was a miniature combat of gladiators, but with no appeal for mercy on the part of the vanquished. Much evidently depended on the best hold, as in wrestling, for there was no dislodging an ant once she had secured it. Under the lens the comparatively great strength and the skill and relentless ferocity of these miniature warriors became more evident and was astonishing to witness.
A bird's-eye view of the battle-field revealed no plan of action nor any directing genius. It was every one for himself—or rather herself—but there was absolute unity of purpose. Occasionally some could be seen running about with the heads of the vanquished suspended on their antennæ, whereon the jaws had closed in the death-struggle, not again to be relaxed. These ants appeared to seek no relief from such a monstrous encumbrance, nor seemingly was any offered by their comrades. Others were crawling on an uneven number of legs in search of new foes. The cause of such a conflict among ants of the same species remains a mystery—one of the many mysteries.
Every year the red ants raid the common blacks for the purpose of making slaves—a most highhanded proceeding. This season I came upon the invading host marching up the road about ten in the morning of July 28th. The invasion had but lately begun, as the ants were carrying no pupæ; it was the skirmish line. As the column advanced, frequent and rapid communication took place between individuals and stragglers who were coming back. Later, when the raid was well under way, there was little of this. The nest of the red ants was by the side of a path in the woods which led out to the wagon road, while the negroes were domiciled some distance up this lane. Now the column of red ants followed the path and the road the entire way, in place of going directly through the bushes, though it doubled the distance, which thus amounted to some fifty yards.
Red ants were soon pouring out of the various openings in the nest of the blacks, carrying both pupæ and larvæ, and rarely one passed with a bunch of small white eggs. Several black queens came out of the nest, and as they emerged were set upon by red ants, which tried to hold them by their wings. They managed, however, to throw off their assailants, and ran under my feet, where they were followed by a score of black workers, all of whom crowded under the soles of my shoes as I stood on the loose gravel. At noon I timed the ants and found that, on the average, forty pupæ and larvæ were carried past a given point every minute. Two unbroken columns now extended the entire distance between the nests, one advancing and the other returning.
Occasionally one passed carrying a portion of a black ant, a head and thorax, or an abdomen. Again, one would appear with a live black, which, when liberated by me, frantically made her escape. Very young negroes when carried off were never injured. On one occasion several red ants were struggling with a black, and among them was a black who fought against her own friend. This is the only case in which I saw a black ant help the enemy in this way—a traitor, evidently, but presumably one whose pupa had been captured the year before and reared in slavery. Whereas the red ants always came to each other's assistance, the blacks rarely did so.
By five o'clock the raid was practically over for the day. It ceased as suddenly as it had begun. Early in the struggle a slender, straggling column had diverged from the main line, about half way between the nests. I now found the entire body of ants moving in this new direction. The one raid over, they had undertaken another upon a colony of blacks some twenty-five yards distant, and were transporting the pupæ and larvæ at about the same rate as before. To reach this nest, the column must cross the wagon road, and here a number were crushed from time to time by passing vehicles. But the marching army passed by with the stolen pupæ and paid no heed to their wounded comrades. This second foray ceased before nightfall.
The following morning by ten o'clock the raid had been renewed and a great stream of ants were bearing away pupæ as before. Whenever the column moved over dry leaves its progress was distinctly audible, a rustling sound suggesting the curiously dry crik crik of a serpent. The footfall of the ants was as incessant as the patter of rain; a barefooted insect host, a rabble of sans culottes, and the sound of their marching feet reached my listening ears, as it were in the clouds above them.