Off at one side of the general cleaning and reconstruction areas was a pitiful assemblage of cripples which had had enough energy to crawl back, but which did not attempt, or were not allowed, to enter the nest proper. Some had one or two legs gone, others had lost an antenna or had an injured body. They seemed not to know what to do—wandering around, now and then giving one another a half-hearted lick. In the midst was one which had died, and two others, each badly injured, were trying to tug the body along to the edge of the board. This they succeeded in doing after a long series of efforts, and down and down fell the dead ant. It was promptly picked up by several kitchen-middenites and unceremoniously thrown on the pile of nest-débris. A load of booty had been dumped among the cripples, and as each wandered close to it, he seemed to regain strength for a moment, picked up the load, and then dropped it. The sight of that which symbolized almost all their life-activity aroused them to a momentary forgetfulness of their disabilities. There was no longer any place for them in the home or in the columns of the legionaries. They had been court-martialed under the most implacable, the most impartial law in the world—the survival of the fit, the elimination of the unfit.
The time came when we had to get at our stored supplies, over which the army ants were such an effective guard. I experimented on a running column with a spray of ammonia and found that it created merely temporary inconvenience, the ants running back and forming a new trail. Formaline was more effective, so I sprayed the nest-swarm with a fifty-per-cent solution, strong enough, one would think, to harden the very boards. It certainly created a terrible commotion, and strings of the ants, two feet long, hung dangling from the nest. The heart of the colony came into view, with thousands of eggs and larvæ, looking like heaps of white rice-grains. Every ant seized one or the other and sought escape by the nearest way, while the soldiers still defied the world. The gradual disintegration revealed an interior meshed like a wasp's nest, chambered and honeycombed with living tubes and walls. Little by little the taut guy-ropes, lathes, braces, joists, all sagged and melted together, each cell-wall becoming dynamic, now expanding, now contracting; the ceilings vibrant with waving legs, the floors a seething mass of jaws and antennæ. By the time it was dark, the swarm was dropping in sections to the floor.
On the following morning new surprises awaited me. The great mass of the ants had moved in the night, vanishing with every egg and immature larva; but there was left in the corner of the flat board a swarm of about one-quarter of the entire number, enshrouding a host of older larvæ. The cleaning zones, the cripples' gathering-room, all had given way to new activities, on the flat board, down near the kitchen middens, and in every horizontal crack.
The cause of all this strange excitement, this braving of the terrible dangers of fumes which had threatened to destroy the entire colony the night before, suddenly was made plain as I watched. A critical time was at hand in the lives of the all-precious larvæ, when they could not be moved—the period of spinning, of beginning the transformation from larvæ to pupæ. This evidently was an operation which had to take place outside the nest and demanded some sort of light covering. On the flat board were several thousand ants and a dozen or more groups of full-grown larvæ. Workers of all sizes were searching everywhere for some covering for the tender immature creatures. They had chewed up all available loose splinters of wood, and near the rotten, termite-eaten ends, the sound of dozens of jaws gnawing all at once was plainly audible. This unaccustomed, unmilitary labor produced a quantity of fine sawdust, which was sprinkled over the larvæ. I had made a partition of a bit of a British officer's tent which I had used in India and China, made of several layers of colored canvas and cloth. The ants found a loose end of this, teased it out and unraveled it, so that all the larvæ near by were blanketed with a gay, parti-colored covering of fuzz.
All this strange work was hurried and carried on under great excitement. The scores of big soldiers on guard appeared rather ill at ease, as if they had wandered by mistake into the wrong department. They sauntered about, bumped into larvæ, turned and fled. A constant stream of workers from the nest brought hundreds more larvæ; and no sooner had they been planted and débris of sorts sifted over them, than they began spinning. A few had already swathed themselves in cocoons—exceedingly thin coverings of pinkish silk. As this took place out of the nest,—in the jungle they must be covered with wood and leaves. The vital necessity for this was not apparent, for none of this débris was incorporated into the silk of the cocoons, which were clean and homogeneous. Yet the hundreds of ants gnawed and tore and labored to gather this little dust, as if their very lives depended upon it.
With my hand-lens focused just beyond mandible reach of the biggest soldier, I leaned forward from my insulated chair, hovering like a great astral eye looking down at this marvelously important business of little lives. Here were thousands of army ants, not killing, not carrying booty, nor even suspended quiescent as organic molecules in the structure of the home, yet in feverish activity equaled only by battle, making ready for the great change of their foster offspring. I watched the very first thread of silk drawn between the larva and the outside world, and in an incredibly short time the cocoon was outlined in a tissue-thin, transparent aura, within which the tenant could be seen skilfully weaving its own shroud.
When first brought from the nest, the larvæ lay quite straight and still; but almost at once they bent far over in the spinning position. Then some officious worker would come along, and the unfortunate larva would be snatched up, carried off, and jammed down in some neighboring empty space, like a bolt of cloth rearranged upon a shelf. Then another ant would approach, antennæ the larva, disapprove, and again shift its position. It was a real survival of the lucky, as to who should avoid being exhausted by kindness and over-solicitude. I uttered many a chuckle at the half-ensilked unfortunates being toted about like mummies, and occasionally giving a sturdy, impatient kick which upset their tormentors and for a moment created a little swirl of mild excitement.
There was no order of packing. The larvæ were fitted together anyway, and meagerly covered with dust of wood and shreds of cloth. One big tissue of wood nearly an inch square was too great a temptation to be let alone, and during the course of my observation it covered in turn almost every group of larvæ in sight, ending by being accidentally shunted over the edge and killing a worker near the kitchen middens. There was only a single layer of larvæ; in no case were they piled up, and when the platform became crowded, a new column was formed and hundreds taken outside. To the casual eye there was no difference between these legionaries and a column bringing in booty of insects, eggs, and pupæ; yet here all was solicitude, never a bite too severe, or a blunder of undue force.
The sights I saw in this second day's accessible nest-swarm would warrant a season's meditation and study, but one thing impressed me above all others. Sometimes, when I carefully pried open one section and looked deep within, I could see large chambers with the larvæ in piles, besides being held in the mandibles of the components of the walls and ceilings. Now and then a curious little ghost-like form would flit across the chamber, coming to rest, gnome-like, on larva or ant. Again and again I saw these little springtails skip through the very scimitar mandibles of a soldier, while the workers paid no attention to them. I wondered if they were not quite odorless, intangible to the ants, invisible guests which lived close to them, going where, doing what they willed, yet never perceived by the thousands of inhabitants. They seemed to live in a kind of fourth dimensional state, a realm comparable to that which we people with ghosts and spirits. It was a most uncanny, altogether absorbing, intensely interesting relationship; and sometimes, when I ponder on some general aspect of the great jungle,—a forest of greenheart, a mighty rushing river, a crashing, blasting thunderstorm,—my mind suddenly reverts by way of contrast to the tiny ghosts of springtails flitting silently among the terrible living chambers of the army ants.
On the following morning I expected to achieve still greater intimacy in the lives of the mummy soldier embryos; but at dawn every trace of nesting swarm, larvæ, pupæ and soldiers was gone. A few dead workers were being already carried off by small ants which never would have dared approach them in life. A big blue morpho butterfly flapped slowly past out of the jungle, and in its wake came the distant notes—high and sharp—of the white-fronted antbirds; and I knew that the legionaries were again abroad, radiating on their silent, dynamic paths of life from some new temporary nest deep in the jungle.