This evening he was not hungry, and he was in a hurry.

In spite of these two facts he stood for some minutes in the shadows near the pond.
The beavers had already begun their night's work.

Muskwa soon understood the significance of the shimmering streaks that ran swiftly over the surface of the water.

At the end of each streak was always a dark, flat head, and now he saw that most of these streaks began at the farther edge of the pond and made directly for a long, low barrier that shut in the water a hundred yards to the east.
This particular barrier was strange to Thor, and with his maturer knowledge of beaver ways he knew that his engineering friends--whom he ate only occasionally--were broadening their domain by building a new dam.

As they watched, two fat workmen shoved a four-foot length of log into the pond with a big splash, and one of them began piloting it toward the scene of building operations, while his companion returned to other work.