Beaver, Castor canadensis, Minnesota, Wisconsin, animal, birch, brown, chewing, cone-shaped stumps, dam, dam-building, destructive, forage, fur, gnaw, hide, lakes, large teeth, mammal, nature, northern, nuisance, paddlelike, pelt, polar, river, rodent, scaly, slap, slap water, streams, summer, trap, trapped, trapping, tree, underwater, water, wild, wildlife