The beaver is a primarily nocturnal, large, semi-aquatic rodent. Castor includes two extant species, Castor canadensis and
Castor fiber. Beavers are known for building dams, canals, gullys, log cabins, and lodges (homes). They are the second-largest
rodent in the world. Their colonies create one or more dams to provide still, deep water to protect against predators, and
to float food and building material.