Beaver teeth never stop growing and become sharper with use. A beaver's tail serves as a prop when the animal sits upright to feed and as a rudder and diving plane when swimming. It is seldom used for actual locomotion. Beavers will slap their tail on the surface of the water as an alarm signal. This signal warns other beavers of the presence of a predator.
Beavers can stay submerged for up to fifteen minutes.
Beaver kits have been observed swimming when only 13 hours old. Contrary to popular belief, beaver cannot determine which way a tree will fall. Cut trees usually fall toward the water because they grow at a lean toward the light of the open space above the water.