So the two burros were taken to a small nearby clearing where buffalo grass offered a juicy repast for them. Having hobbled them to keep them from straying, Polly led the way back to the beaver-dam.
"If you were over there to examine those cut aspens you would find each one about eighteen inches long and about one and a half inches thick. The beavers always build near an aspen grove, as it is their food, but not finding a grove near the water, they have to swim up or down until they reach what they need. That is why you find their huts on water," explained Polly.
"But I've heard they are water animals."
Before Polly could reply, a sleek head bobbed up from the water near one of the huts and Eleanor gasped with surprise. The beaver swam to the opposite bank where the trees had been cut down. He climbed quickly out of the stream and started to roll a heavy log over the ground until it splashed down into the pond. He then jumped after it and continued rolling and pushing it along till he reached the dam. Instantly, more beavers came out from the huts and assisted in towing the log to their dam of aspens.
"Oh, oh, Polly!" whispered Eleanor in excited astonishment, but Polly held her finger over her lips in warning.
"I do believe they plan to build a new dam further up-stream, Nolla. If that is so, we will have something worth while to watch for during the next few days. Just now they are repairing the old houses for the Winter, and that log is to be a bulwark about which green cuttings of willow and young aspens can be woven as a partial strainer for the water. The débris that thus collects in the chinks between the cuttings, makes the dam firmer and yet more flexible than a solid structure would."
Just then, the sound of a falling tree made Eleanor jump and look across the stream.
"Other industrious beavers cutting down another tree," explained Polly.
"How do they ever do it, Poll?"
"If you watch, you will see that beaver go to work."