"rodere"- to gnaw; "dent" -teeth
Beavers
"Beaver dams may be good for nature, but why do beavers build them? In short, a dam creates a body of water that makes a relatively safe neighborhood for a beaver family. Since beavers are very good swimmers but fairly slow on land, deeper water creates a habitat where they can find more protection from bears and other predators.
Beavers are nocturnal but they don't spend all night in the ponds or slow-moving streams created by their dams. Instead, they build lodges -- houses where a beaver couple and their children live. Beavers gather sticks, mud, rocks and other available materials to shape these mound-like structures. A group of lodges forms a beaver colony and houses multiple beaver families." taken from How Stuff Works
Beaver Lodge
Fox Squirrel
Prairie Dog
Other animals in chapter 7