"A swarm of sand-flies."
"Sand-flies! what are they?" asked Jack.
"Wait, and I'll show you," replied Ned, going out and stirring up the fire so as to make a light. Meantime the boys rubbed and writhed and turned themselves about in something like agony, for, though they suffered no severe pain at any one spot, their whole bodies seemed to be covered with red pepper. Every inch of their skins was inflamed, and the more they rubbed the worse the irritation became.
When Ned had made a bright light, he showed his companions what their tormentors were. Jack and Charley saw some very minute flying insects—true flies indeed—not much larger than the points of pins. There were millions of the creatures. The whole air seemed full of them indeed, and wherever one rested for a moment upon the skin of its victim, there was at once a pricking sensation, followed by the intolerable burning and irritation already mentioned.
Charley was at first incredulous. "You don't mean to tell me," he said, "that those little gnats have done all this."
"Yes, I do," answered Ned, "and more than that, I have known them to kill a horse, tormenting him to death in a few hours. They'll get under a horse's hair by millions and literally cover him, until you can see the hair move with them. But they are not gnats."
"But, see here, Ned," said Jack; "when I barely touch one of the creatures, it not only kills him but distributes him pretty evenly over the surrounding surface. They haven't strength enough to hang together."
"Yes, I know," replied Ned; "what of that?"
"Why, how can such things bite so? and especially how can they force their way through our blankets and clothes? I should think they'd tear themselves to pieces in the attempt."
"So should I, if I didn't know better; but as a matter of fact they do manage to get through without dulling their teeth, as we have proof."