Pit number five had become a shambles. Number five was one of the series of holes dug along the Convict Trail to entrap unwary walkers of the night—walkers or hoppers, for frogs and toads of strange tropical sorts were the most frequent victims. It was dug wide and deep on the slope of an ancient dune of pure white sand, a dune deep hidden in the Guiana jungle, which had not heard the rush and slither of breaking waves for centuries untold. All around this quiet glade was an almost pure culture of young cecropia trees. Day after day the pit had entrapped big beetles, rarely a mouse of some unknown species, more frequently a frog.

Now I stood on the brim, shocked at an unexpected sight. A horde of those Huns of the jungle, army ants, had made their drive directly across the glade, and scores of fleeing insects and other creatures had fallen headlong into this deep pit. From my man's height it was a dreadful encounter, but squatting near the edge it became even more terrible; and when I flattened myself on the sand and began to distinguish individuals and perceive the details from an ant's point of view, I realized the full horror and irresistibility of an assault by these ants.

One is not strongly affected by the dying struggles of a single grasshopper captured by a cuckoo or flycatcher. An individual roach being torn to pieces moves one but slightly. A batrachian, however, has more claim on our emotions, and my sympathy went out to a small, sandy-white frog who was making a brave fight for his life. The pit was alive with a host of the army ants, and wherever the little frog hopped, some soldier or heavy-jawed worker soon found him and sank jaws into his soft skin. With frantic scratching the frog would brush it off and leap again, only to be again attacked. The most horrible thing about these ants is their leaping ability. The hop of a bird or the jump of a toad when going about their usual business of life, if we think of it at all, is only amusing. But the sudden leap of a bulldog or tarantula, and the corresponding vicious attack of these ants, is particularly appalling. I saw a soldier leap a full inch and a half toward the landing thud of the frog and bite and sting at the instant of contact. I did not dare go into the pit. No warm-blooded creature could have stood the torture for more than a few seconds. So I opened my umbrella and reaching down, scooped up the sand-colored frog. A half-dozen ants came up in the same instrument, but I evaded them and tied up the tormented batrachian in my handkerchief.

My next glance into the pit showed a large toad, squatted on a small shelf of sand, close to the edge of a crowded column of ants. He was a rough old-chap, covered with warts and corrugations, and pigmented in dark gray, with mottlings of chocolate and dull red and occasional glints of gold. He was crouched flat, with all his fingers and toes tucked in beneath him. His head was drawn in, his eyes closed, and all his exposed surface was sticky with his acid perspiration—the sweat of fear. He knew his danger—of that there was no doubt—and he was apparently aware of the fact that he could not escape. Resignedly he had settled on the very line of traffic of the deadly foe, after intrenching himself and summoning to his aid all the defenses with which nature had endowed him. And he was winning out—the first vertebrate I have ever known to withstand the army ants. For a few minutes he would be ignored and his sides would vibrate as he breathed with feverish rapidity. Then two or three ants would run toward him, play upon him with their antennÆ, and examine him suspiciously. During this time he was immovable. Even when a soldier sank his mandibles deep into the roughened skin and wrenched viciously, the toad never moved. He might have been a parti-colored pebble embedded in its matrix of sand. Once, when three bit him simultaneously, he winced, and the whitish, acrid juice oozed from his pores. Usually the ants were content with merely examining him. I left him when I saw that he was in no immediate danger.

One other creature was quiescent in the pit and yet lived: a big, brown, hardbacked millipede. Like the frog, he fully realized his danger and had sunk his bulk partly into the sand, bending down head and tail and presenting only mailed segments. A mob of ants were trying vainly to bite their way into this organic citadel.

For the dozens of grasshoppers, crickets, roaches, beetles, spiders, ants, and harvest men, there was no escape. One daddy-long-legs did a pitiful dance of death. Supported on his eight long legs, he stood high out of reach of his assailants. He was balanced so exactly that the instant a feeling antenna touched a leg, he would lift it out of reach. Even when two or three were simultaneously threatened, he raised them, and at one time stood perfectly balanced on four legs, the other four waving in air. But his kismet came with a concerted rush of half a dozen ants, which overbore him, and in a fraction of time his body, with two long legs trailing behind, was straddled by a small worker and borne rapidly away.

I now flattened myself on an antless area at the edge of the pit and studied the field of battle. In another half-hour the massacre was almost over. Five double, and often quadruple, columns were formed up the sandy cliffs, and the terrific labor of carrying out the dead victims began. The pit was five feet deep, with perfectly straight sides, which at the rim had been gutted by the rain, so that they actually overhung. Yet the ants which had half-climbed, half-tumbled and rolled their way to the bottom in the wake of their victims, now set themselves to solving the problem of surmounting these cliffs of loose, crumbling grains, dragging loads which, in most cases, were much heavier than themselves. Imagine a gang of men set to carrying bundles of one to two hundred pounds up perpendicular cliffs twelve hundred feet in height, and the task of the army ants is made more vivid. So swiftly did they work and so constantly shifted their formations and methods of meeting and surmounting difficulties, that I felt as I used when looking at a three-ring circus. I could perceive and record only a small part of the ingenious devices and the mutual assistance and sharing of the complicated conditions which arose at every step.

Among the frightened victims, even for those endowed with excellent eyesight and powerful flight, there was only hopeless confusion and blind terror. Instead of directing their flight upward, they drove from side to side. Those whose leaps should have carried them out, simply kicked out blindly and brought up against the sandy walls.

If leaf-cutting ants had been at work here, there would have been a certain amount of cooperation. Certain ones would have cut leaves, other individuals would have picked them up and transported them. But with the army ants this mutual assistance was sublimated, developed to a quintessence of excellence. If I, seated on the rim, overlooking the whole, had been an all-powerful spirit, gifted with the ability to guide by thought simultaneously all the ants within sight, such guidance could not have bettered the cunning cooperation, the unexpectedly clever anticipation of trouble, the marvelous singleness of purpose and manifold effectiveness exhibited by these astounding creatures.

First, as to the personnel of the army ants. Roughly I divided them into two categories, white-heads and black-heads. The latter were by far the more numerous and, as a rule, were smaller, with less powerful jaws. But this did not mean that the white-heads were all soldiers. Most of them indeed were the hardest workers. Between the great extremes of size in each of these two types, there seemed to exist only a difference of degree. The smallest black-head laborers, only a little more than one-fifth of an inch long, did their bit, flew like bull pups at any prey which showed signs of life, and staggered bravely along with any piece of loot which their short legs could straddle.

The white-heads, twice as large, were the strong men of the community, putting all their activity into the labor, shouldering, pushing, dragging, lifting, singly or in unison. These persons had powerful jaws, but jaws which were stout and scissor-edged. The largest of the white-heads were armed with reaping-hooks, long inwardly-pronged jaws, curved like the tushes of ancient mammoths, too specialized for carrying loads, but well adapted for defense of the most powerful character. Yet, as we shall see, even these were not too proud to work, when occasion demanded it. But their jaws were so enormous that they had to carry themselves very erect, and they could not make quite as good time as the other castes.

All had reddish brown abdomens, with darker thoraxes and white or black heads. These heads bulged on each side like the domes of observatories. Exactly in the center of each dome, looking like the jet-black head of a tiny pin, was the single remaining facet of the eye, the degenerate residue of the hundreds which were present in their ancestors, and which the perfect males and females still possess and look through. Even this single eye is a sham, for its optic nerve dies out before the brain ganglion is reached; so we come to the astounding realization that these ants are totally blind, and carry on all their activities through the sense or senses residing in those marvelous quivering antennÆ. Here are beings spending all their lives in ceaseless changing activities, meeting and coping with constantly new conditions, yet wholly blind. Their sense of smell dominates their judgment of substance, and the moment an army ant reached my moccasin he sank jaws and sting deep into the fabric as instinctively and instantly as when he executed the same manoeuvers more effectively on my hand.

Keeping this handicap in mind, the achievements of these little creatures assumed a still greater significance, and with renewed interest and appreciation I again surveyed the scene in the amphitheater before me. When the majority of the pit victims had been slain, the process of carrying them up to the surface began. The hordes of ravening ants resolved themselves, as I have said, into five distinct columns of traffic which, inch by inch, fought for a footing up three of the four sides.

Half of the bottom of the pit was a sort of flat table-land several inches higher than the rest, and the first thing the ants did was to carry all their booty to this steppe, in pieces or bodily, some of the unfortunate creatures still protesting weakly as they were dragged along. In fifteen minutes the lowest part of the pit bottom was deserted, and after much hesitation I vaulted down and found a footing reasonably safe from attack.

Two traffic columns had already reached the summit, and the others were forging rapidly ahead. All used a similar method of advance. A group of mixed castes led the way, acting as scouts, sappers, and miners. They searched out every slope, every helpful step or shelf of sand. They took advantage of every hurdle of white grass-roots as a welcome grip which would bind the shifting sand grains. Now and then they had to cross a bare, barren slope with no natural advantages. Behind them pressed a motley throng, some still obsessed with the sapper instinct, widening the trail, tumbling down loose, dangerous grains. Some bore the first-fruits of victory, small ants and roaches which had been the first to succumb. These were carried by one, or at most by two ants, usually with the prey held in the jaws close beneath the body, the legs or hinderpart trailing behind. In this straddling fashion the burden was borne rapidly along, an opposite method from the overhead waving banners of the leaf-cutters.

With these came a crowd of workers, both white and black-headed, and soldiers, all empty-jawed, active, but taking no part in the actual preparation of the trail. This second cohort or brigade had, it seemed to me, the most remarkable functions of any of the ants which I saw during my whole period of observation. They were the living implements of trail-making, and their ultimate functions and distribution were so astounding, so correlated, so synchronized with the activities of all the others that it was difficult not to postulate an all-pervading intelligence, to think of these hundreds and thousands of organisms as other than corpuscles in a dynamic stream of life controlled by some single, outside mind.

Here, then, were scores of ants scrambling up the steep uneven sides, over ground which they had never explored, with unknown obstacles confronting them at every step. To the eye they were ants of assorted sizes, but as they advanced, numbers fell out here and there and remained behind. This mob consisted of potential corduroy, rope-bridges, props, hand-rails, lattices, screens, fillers, stiles, ladders, and other unnamable adjuncts to the successful scaling of these apparently impregnable cliffs. If a stratum of hard sand appeared, on which no impression could be made, a line of ants strung themselves out, each elaborately fixing himself fast by means of jaws and feet. From that moment his feverish activity left him: he became a fixture, a single unit of a swaying bridge over a chasm; a beam, an organic plank, over which his fellows tramped by hundreds, some empty, some heavily laden. If a sudden ascent had to be made, one ant joined himself to others to form a hanging ladder, up which the columns climbed, partly braced against the sandy wall.

At uncertain, unguarded turns a huge soldier would take up his station, with as many functions and duties as a member of the Broadway traffic squad. Stray, wandering ants would be set right by a single twiddle of antennÆ; an over-burdened brother would be given a helping jaw and assisted for some distance to the end of his beat. I was especially interested in seeing, again and again, this willingness to help bear the burdens. It showed the remains of an instinct, inhibited by over-development, by ultra-specialization of fighting paraphernalia, still active when opportunity gave it play. At the first hint, by sound or smell, of danger, the big soldier whirled outward and, rearing high on his legs, brandished his mighty blades in mid-air. Here was an ideal pacifist, who could turn his sword into a plowshare at will, and yet keep the former unsheathed for instant use.

When I watched more closely, I detected more delicate gradations of mutual aid. At the same level in two columns of ascent, the same stratum of hard sand was encountered. To one column the sand presented a rough surface which gave good foothold. Here the single line of ants which was ranged along the lower edge of the trail, in lieu of hand-rail, all faced downward, so that the ants passing above them walked partly on the abdomens and partly on the hind legs of their fellows. In the second column, the surface of the sand was smooth, and here the burdened ants found great difficulty in obtaining a foothold. In this instance the supporting gang of ants faced upward, keeping their place solely by their six sturdy legs. This left head and jaws free, and in almost every case they helped the passage of the booty by a system of passing from jaw to jaw, like a line of people handing buckets at a fire. The rightful carriers gave up their loads temporarily and devoted their attention to their own precarious footing.

I learned as much from the failures of this particular formation as from its successes. Once a great segment of a wood-roach was too much for the gallant line clinging to the sides of the pit, and the whole load broke loose and rolled to the bottom. Of the hand-rail squad only two ants remained. Yet in four minutes another line was formed of fresh ants,—ants who had never been to the spot before,—and again the traffic was uninterrupted. I saw one ant deliberately drop his burden, letting it bounce and roll far down to the bottom of the pit, and instantly take his place in the line of living guardrails. The former constituents of the line had clung to the roach segment through all its wild descent, and until it came to rest at the bottom. Without a moment's pause, they all attacked it as if they thought it had come to life, then seized it and began tugging it upward. In a fraction of time, without signal or suggestion or order, the hand-rails had become porters. The huge piece of provender had rolled close to an ascending column on the opposite side of the pit, and up this new trail the bearers started, pulling and pushing in unison, as if they had been droghers and nothing else throughout the whole of their ant-existence.

One climax of mutual assistance occurred near the rim of the pit on a level with my eyes, where one column passed over a surface which had been undermined by heavy rain, and which actually overhung. I watched the overcoming of this obstacle. All the ants which attempted to make their way up at this point lost their footing and rolled headlong to the bottom. By superformicine exertions a single small worker at last won a path to the rim at the top. Around the edge of the pit innumerable ants were constantly running, trying, on their part, to find a way down. The single ant communicated at once with all which came past, and without hesitation a mass of the insects formed at this spot and began to work downward. This could be done only by clinging one to the other; but more and more clambered down this living ladder, until it swayed far out over the vastness of the pit, three inches in length. I had never lost sight of the small worker, who had turned on his tracks and was now near the bottom of the ladder, reaching wildly out for some support—ant, grass, or sand. I was astonished to see that, as the length and consequent weight of the dangling chain increased, the base support was correspondingly strengthened. Ant after ant settled itself firmly on the sand at the top, until a mat of insects had been formed, spread out like animate guy-ropes.

At last the ultimate ant in the rope touched the upraised jaws of the soldier far below. The contact acted like an electric shock. The farthest ant in the guy-rope gang quivered with emotion, a crowd of ants climbed down and another up, and bits of insect and spider prey began to appear from the depths of the pit, over the living carpet suspended from the brim. For an inch the droghers climbed over the bodies braced against the cliff. Then, where the surface became smooth, the dangling chain came into use. Before the rim of the pit was reached, the chain had become a veritable hollow tube of ants, all with heads inward, and through this organic shaft passed the host from the ascending column. But it was far more than any mechanically built tube. When an extra large piece of loot came up, the tube voluntarily enlarged, the swelling passing along until the booty and its bearers emerged at the top.

Within five minutes after this last column was completed, there passed over it, out of the pit, a daddy-long-legs with legs trailing, perhaps the same one which I had seen in the tragic little dance of death. There followed two silvery-gray ants, a wood-roach in two installments, part of a small frog, three roaches, and two beetles. These latter gave a great deal of trouble and tumbled down the cliff again and again.

When all the columns were established and the provision trains in full movement, I leaped out and scouted round for the rest of the army. I found that the pit was only an incident. In all directions lines of ants poured past, carrying booty of all sizes and descriptions. Here and there the huge soldiers walked slowly along the outskirts, directing stragglers, looking for danger, snapping at any roach or strange ant which rushed frantically by, and holding it until it was carried off by nearby workers.

I followed a column over logs and leaves to where it ascended a cecropia tree. A harvest of small arboreal insects was being gleaned high overhead. As I watched, there came a heavy downpour of rain, a typical shower of the tropics, with a scattering of heavy drops out of the full sunshine and then a sudden clouding and a straight deluge for a few minutes. The reaction of the ants was interesting. They did not like the water, and it was comical to see them tumble over one another to get under shelter. Like the doorways of city shops in a shower, every curled-up leaf was packed, and from every crevice of bark projected sundry abdomens and hind legs for which there was no room inside. When the bearer of a large bag of booty found a convenient corner, he backed into it and left his meat sticking out in the rain.

After the shower all came forth at full speed, but for some minutes there was considerable confusion. The sluice of water had evidently washed away much of the scent which stood for guide-posts, directing signs, and pointing hands along the trail. Only after many false starts were the old pathways discovered and again traversed. In one place the ants climbed a huge log and marched along the top for six or seven yards. I timed them carefully and found that on this straightaway track their average speed was two and a half feet in ten seconds. So they covered a mile in three hours and a half, and in all the army ants I have ever watched this rate of speed never slackens; in fact, it frequently greatly increases. When hot on the scent of prey they double their usual gait.

There are as many ludicrous sights to be seen in the ranks of army ants as there are among the banner-decked processions of the leaf-cutters. Along the tree-trunk track came three big white-heads straddling an inch-worm—in this case an inch-and-a-half-worm. They leaned forward and downward, the heads of those behind overlapping the abdomens in front, and they looked for all the world like the riders of an old-fashioned three-seated bicycle, spurting along the trail. Another simile, even more vivid, evoked the vision of some weirdly constructed, elongated myriopod with eighteen legs. After a hard fight, in the course of which I was stung twice, I unseated the trio and took the measuring worm away from them. As I lifted it from where it had fallen, at least fifty ants hurled themselves at the spot, jaws snapping, trembling with violent rage. I walked ten feet away and dropped the worm in the midst of another column, and within an equal number of seconds three new white-heads had mounted it and were hustling it along—the replicas in appearance and method of the first team.

Many species of stranger ants were killed and carried off as food, but now and then I noted a most significant exception. In three different parts of the glade I saw good-sized, pale, flesh-colored ants which walked unharmed in the very ranks of the terrible host. Unharmed they were, but not wholly above suspicion, and their progress was not an easy one. For every unburdened ant which passed leaped at the pale one, antennaed it fiercely for a moment and reluctantly released it. One could read their indecision as they slowly loosened their hold, turning again and again and waving their antennÆ as if to make sure that it was not better to act on their suspicion and slay at once. Finally, they always passed on. The pale ones had some strange inaudible password, some sensory parole which protected them. And their total lack of fear showed their knowledge of their immunity. Even with the added sense of sight which they possessed, they chose voluntarily to accept this dubious, reluctantly accorded friendship. But it was probable that, even if they lived in the very community or nest of the army ants, theirs was the hard-earned dependence of neutrals who were liable to be knocked down at a moment's notice, and searched for any strange, inimical scent which would spell instant death.

In one place the army column made a slight dÉtour round a hillock of sandgrains upon which a host of tiny brown ants was laboring. I thought it remarkable that such immunity should be accorded these dwarfs, and I sought the reason. It was forthcoming at once when I gingerly lifted a big soldier with the forceps and dropped him on the ant-hill. What occurred was a replica of the usual army ant scene, but enacted as if viewed through the large end of an opera-glass. Scores of the minute brown chaps rushed forth and for a moment fairly overbore the white-headed giant. Indeed, before he could recover he was dragged partly down a sandy hole. His jaws brandished and champed, but his assailants were so small that they slipped through them unharmed. Many actually seized the jaws themselves and were hurled through the air as they snapped together. Regaining his feet, the great army ant staggered off and, fortunately for him, rolled down a slope into another column of his own kind. Here he freed himself little by little, scraping off the minute fighting browns with the help of two very small workers, whose jaws, being much less in size, were better able to grip the diminutive furies. Their assistance was half-hearted, and the odor of the dead and dying pygmies was distinctly disliked by them. They were apparently well aware of the capabilities of these small cousins, and held them in high respect. This outburst of successful defense on the part of the small ants was unexpected. I glanced back at their hill and saw them unconcernedly piling up grains as if nothing had occurred to disturb them. I wondered if, with senses perfectly attuned, with an enlarging-glass ability of observation, one might not find still lesser communities which would in their turn consider the little brown ants as giants, and on the space of a pin's head attack them and fly at their throats.

A species of silvery-gray ant which was abundant in the glade was an object of special enmity, and even after one of these was killed and being carried along, passing army ants would rush up and give it a vicious, unnecessary nip. One such ant made its escape from the hold of a small worker; but before it had taken ten steps it was actually buried under a rolling mass of army ants. The flying leap with which these athletes make their tackle would delight the heart of any football coach, although their succeeding activities belong rather to savage warfare. Termites, or so-called white ants, are, curiously enough, immune from attack. Yet these slow-moving, fat-bodied creatures would seem first-rate food, and the fight which they could put up would not stand an instant before a concerted rush of battling army ants. The saving character is doubtless odor or taste. I dropped a tunnelful of these insects in the path of the army ants and they were quite ignored, although the black-and-white-headed fellows were terribly angry and excited.

I coveted a small beetle of peculiar pattern which the ants were hurrying along, and in taking it from them I accidentally cut an army ant in two. His abdomen rolled down a small slope and caused considerable panic among his fellows. They formed a ring round it and waved their antennÆ in mid-air, the scent of the blood of their own kind causing them to forget hurry and burdens and their normal activities. The front part of the ant seemed but little inconvenienced and endeavored to seize and carry the load it had dropped. Little by little it began to realize that all was not right, and after one or two attempts to turn and investigate, it ran rapidly down the trail. I made a dab at it to put it out of what seems better called inconvenience than misery, but succeeded only in bisecting the thorax, so that there remained the head and front pair of legs. These lost nothing in activity, and by means of the single pair of legs the head rowed itself rapidly along, its antennÆ twiddling vigorously those of every ant it met. This was uncanny, a little too much, and I ground the fraction of ant to powder. No wonder the army ant is such a virile creature, endowed with the most extreme emotions, when, with such a small section of its anatomy remaining it can continue to show such astounding activity.

One could study for hours the interactions among the army ants themselves. More than once I saw a good-sized ant transporting one of its fellows, exactly as it would carry a bit of booty. I tried to examine this ant, and to my surprise, both attacked me ferociously. The one which was carried was neither dead, ill, nor disabled, but very much alive. I cannot even suggest an explanation of this phenomenon, as it did not seem an attempt to aid a comrade in distress.

As dusk began to settle down, I found a column of ants which must have discovered and sacked the city of some stranger ants. They were laden with ant-booty: eggs, larvÆ, and dead ants by the hundred. It was comprehensible, but what I did not at first understand was a dense line of ants moving solidly in one direction, all laden with large eggs and immature ants, which they were carrying with great care. A large number of the huge soldiers patrolled the outer flanks of the column, more than I had seen with all the other traffic lines together. I realized at last that I was looking at an actual moving of a portion of the army ant household itself. It was guarded and transported with all the care of which these insects were capable. The infant ants rested safely in the great jaws, the same jaws which all day had been busy slashing and biting and tearing, and carrying food for these same infants.

And now the tropical night began to close down and I made my way back to the sandpit. The last of the columns was making its way out, systematically from the bottom up, each ant following in turn. The moment the last bit of prey passed up the column, by some wonderfully delicate and subtile sense, every ant knew of it, and the corduroy rose, the hand-rails unjointed themselves, the ropes unspliced, the embankments dislodged of their own volition, and stepping-stones took to themselves legs. After hours of total inactivity, these sentient paraphernalia of the via formica became, once more, beings surcharged with ceaseless movement, alert and ready to become a useful cog in the next movement of this myriad-minded machine. I jumped down into the pit. The great gold-spotted toad stretched and scratched himself, looked at me, and trembled his throat. I was not an army ant! The millipede cautiously reared its head from the sand and felt timidly about.

I looked out and saw the last of the mighty army disappearing into the undergrowth. I listened and heard no chirp of cricket, nor voice of any insect in the glade. Silence brooded, significant of wholesale death. Only at my feet two ants still moved, a small worker and a great white-headed soldier. Both had been badly disabled in the struggles in the pit, and now vainly sought to surmount even the first step of the lofty cliff. They had been ruthlessly deserted. The rearing of new hosts was too easy a matter for nature to have evolved anything like stretchers or a Red Cross service among these social beings. The impotence of these two, struggling in the dusk, only emphasized the terrible vitality of their distant fellows. As the last twilight of day dimmed, I saw the twain still bravely striving, and now the toad was watching them intently. A poor-me-one called mournfully from a distance, and I walked slowly toward home.