"Maybe they're at camp eating breakfast. It's still early, you know."

"If they are," said Charley, "then this is the very time to investigate.
We'll look around before anybody gets back."

Glancing once more about the opening to make sure that nobody was in
sight, they stepped from behind their concealing bushes and started across
the open space. But immediately they came to a dead stop. Like
rifle-shots, a succession of sharp sounds rang out, accompanied by
splashing noises. The two boys were at first alarmed, then puzzled. They
looked at each other in amazement.

"What was that?" asked Lew.

"I don't know," replied Charley. "At first I thought somebody was shooting
at us. But I didn't hear any bullets hum. And the noise didn't sound
exactly like a gun, either. It was like the noise a fellow makes when he
hits the water real hard with a board."

In every direction they scanned the clearing. They saw no living things
but the trees. "It's queer," commented Charley. "Let's look at that
nearest tree that's down. Maybe we can learn something from it."

They walked over to the tree, then studied it in amazement. "I never saw
anything like that before," cried Lew. "I don't believe that was ever cut
with an axe. It looks as though it had been gnawed off."

"It has," cried Charley with sudden excitement. "I understand the whole
thing now. We've found a colony of beavers. I never saw a live beaver, but