Will and his companion found the birds scarce although they slipped through the jungle like shadows. As they penetrated deeper among the trees they were careful to walk so that their shadows fell directly behind them, which meant that they were walking in a straight line, along which they could return by observing the same precaution. As they reached a tiny grove of wild oranges, Will's quick eye caught sight of something which gleamed white against the dark trunks, and the two went over to investigate. There they saw a grisly sight. Coiled in a perfect circle were the bones of an anaconda some fifteen feet in length. Every vertebra and rib, and even the small bones of the head and the formidable, recurved teeth, were perfect, while in all the great skeleton there was not a fragment of flesh nor a scale of the skin remaining. Strangest of all, inclosed by the ribs of the snake was the crushed skeleton of a large monkey, which likewise had been cleaned and polished beyond the skill of any human anatomist or taxidermist. Some terrible foe had attacked the great snake while lying helpless and torpid after its heavy meal and had literally devoured it alive. The face of the Indian was very grave as he looked at the gleaming bones before him, and he stared carefully through the adjoining thickets before speaking.
"Puma bad man-eater," he said at last; "cannibal-fish worse; but anicton most dangerous of all. He eat same as fire eats. He kill jaguar, sucurucu, bushmaster, alligator, Indian, white man. He afraid of nothing."
"What is the anicton?" inquired Will, frightened in spite of himself.
Even as he spoke, from far beyond in the jungle came a strange, rustling whisper which seemed to creep along the ground and pass on and on through the woods like the hiss of spreading flames.
"Come," said the Indian, briefly, "I show you." And he led Will farther out into the jungle through which the menacing whisper seemed to hurry to meet them.
Soon small flocks of plain-colored birds could be seen flying low, with excited twitterings, evidently following the course of some unseen objects on the ground. Then there came a rustling through the underbrush, and, in headlong flight, an army of little animals, reptiles, and insects dashed through the jungle. Long brown wood-rats scuttled past, tiny jumping-mice leaped through the air, guiding themselves with their long tails, while here and there centipedes, small snakes, and a multitude of other living creatures sped through the brush as if fleeing before a forest fire.
Suddenly, through a corner of the jungle thrust the van of a vast army of black ants. Through the woods they moved in lines and regiments and divisions, while little companies deployed here and there on each side of the main guard. Like a stream of dark lava, the army flowed swiftly over the ground. As with human armies, this one was made up of different kinds of soldiers, all of whom had different duties to perform. Most numerous of all were the eyeless workers, about half an inch in length, armed with short, but keen, cutting mandibles. These acted as carriers and laborers and reserves, and, although blind, were formidable by reason of their numbers. Larger than the workers, measuring a full inch in length, were the soldiers, with enormous square heads and mandibles pointed and curved like pairs of ice-tongs. These soldiers would drive in each mandible alternately until they met in the body of their victim, and when they met they held. Even if the body of the ants was torn away, the curved clinging jaws still clinched and bit. With the soldiers came companies of butchers, whose jaws had serrated teeth which sheared and cut through flesh and muscle like steel saws. Besides these, there were laborers and reserve soldiers by the million.
Pinto told Will that a large ant-army would take twenty-four hours to pass a given point even when traveling at full speed. As they watched this army, Will saw an exhibition of what it could do. A large agouti in fleeing before them had in some way caught its leg in a tangle of vines and, squealing in terror, tried in vain to escape. Before it could release itself, the rush of the army was upon it, and it disappeared under a black wave of biting, stinging ants, which methodically cut up and carried off every fragment of the animal's flesh, and passed on, leaving behind only a picked skeleton.
As Will watched this hurrying, resistless multitude, although well beyond the path of its advance, he felt a kind of terror, and was relieved when the Mundurucu started back for camp.
"Nothing that lives," said Pinto, as they turned toward the trail, "can stand against the black army."