Beaver
A beaver is large rodent. It is semi-aquatic: some of the time it lives in water, some of the time it lives on land. Beavers are only found in North America and Europe. In Great Britain, for example, they have been deliberately re-introduced. In Europe, they almost died off, but they are returning. There are beavers living in the Elbe and Rhone rivers, as well as in Bavaria, Poland and Scandinavia. Beavers are known for building and keeping dams in rivers.