Castoridae
There are 2 species of beavers , American beaver and Eurasian beaver. Beavers are semi-aquatic mammals found in temperate habitats throughout the northern hemisphere, including Europe, Asia, and North America. They are found wherever there are permanent rivers or streams and enough woody wetland plants for them to eat. American beavers are the largest rodents in North America. They cut down woody plants both to eat and to build their lodges and dams. Through their stream damming and wood-cutting, beavers dramatically change the habitats they live in, often making them more suitable for other species, such as moose.