And Ken chose that quiet hour to begin the map of the river, and to set down in his note-book his observations on the mountains and in the valley, and what he had seen that day of bird, animal, and plant life in the jungle. *VII* *RUNNING THE RAPIDS* Some time in the night a yell awakened Ken. He sat up, clutching his revolver. The white moonlight made all as clear as day. Hal lay deep in slumber. George was raising himself, half aroused. But Pepe was gone. Ken heard a thrashing about outside. Leaping up he ran out, and was frightened to see Pepe beating and clawing and tearing at himself like a man possessed of demons. “Pepe, what’s wrong?” shouted Ken. It seemed that Pepe only grew more violent in his wrestling about. Then Ken was sure Pepe had been stung by a scorpion or bitten by a snake. But he was dumfounded to see George bound like an apparition out of the tent and begin evolutions that made Pepe’s look slow. “Hey, what’s wrong with you jumping-jacks?” yelled Ken. George was as grimly silent as an Indian running the gantlet, but Ken thought it doubtful if any Indian ever slapped and tore at his body in George’s frantic manner. To add to the mystery Hal suddenly popped out of the tent. He was yelling in a way to do justice to the name Ken had lately given him, and, as for wild and whirling antics, his were simply marvelous. “Good land!” ejaculated Ken. Had the boys all gone mad? Despite his alarm, Ken had to roar with laughter at those three dancing figures in the moonlight. A rush of ideas went through Ken’s confused mind. And the last prompted him to look in the tent. He saw a wide bar of black crossing the moonlit ground, the grass, and the blankets. This bar moved. It was alive. Bending low Ken descried that it was made by ants. An army of jungle ants on a march! They had come in a straight line along the base of the little hill and their passageway led under the canvas. Pepe happened to be the first in line, and they had surged over him. As he had awakened, and jumped up of course, the ants had begun to bite. The same in turn happened to George and then Hal. Ken was immensely relieved, and had his laugh out. The stream of ants moved steadily and quite rapidly, and soon passed from sight. By this time Pepe and the boys had threshed themselves free of ants and into some degree of composure. “Say, you nightmare fellows! Come back to bed,” said Ken. “Any one would think something had really happened to you.” Pepe snorted, which made Ken think the native understood something of English. And the boys grumbled loudly. “Ants! Ants as big as wasps! They bit worse than helgramites,” declared Hal. “Oh, they missed you. You always are lucky. I’m not afraid of all the old jaguars in this jungle. But I can’t stand biting, crawling bugs. I wish you hadn’t made me come on this darn trip.” “Ha! Ha!” laughed Ken.