A small part of the tail nearest the beaver's body has the same kind of fur as the body. The rest is covered with black, scaly skin and has only a few stiff hairs. The beaver uses its tail to steer when it swims. The tail is used as a prop when the animal stands on its hind legs to eat or to cut down trees. A beaver slaps its tail on the water to make a loud noise to warn other beavers of danger.
Beaver fur varies from shiny dark brown to yellowish brown.
It looks black when wet. The guard hairs lie over the underfur and protect it. The underfur helps keep a beaver comfortable in the water. This fur traps air and holds it close to the animal's skin. The trapped air acts as a protective blanket that keeps the beaver warm, even in icy water.