The beaver is one of Canada's most recognizable animals and appears on the national five-cent coin. It is the largest rodent in North America, a heavy, thickset swimmer with webbed hind feet, a broad flat tail, and a dense coat. For two centuries the demand for its fur drove the trade that opened much of the country, and by the late 1800s trapping had reduced the beaver to a small fraction of its former numbers across the south. Careful protection in the century that followed allowed the animal to spread once more through nearly all of its old range.

The beaver's most remarkable tools are its front teeth, which never stop growing and are worn down only by constant gnawing; the hard orange outer layer keeps a sharp edge as the softer surface behind it wears away. With these teeth a beaver can bring down a tree as thick as a person's leg in a single night. It uses the cut wood to raise dams across streams, and the pond that gathers behind a dam gives the animal deep water in which to swim and to slip away from predators that hunt on land.