Did silk hats save beavers from extinction? Which is longer, the Hoover Dam, or the biggest beaver dam ever? Are humans naturally monogamous? Learn all about the North American beaver on this episode of Species. Bibliography: https://docs.google.com/document/d/1uufPXkcVlmViyoOMwEQYXw5swayShvOeRh-b_TLL01E/edit?usp=sharing