The river otter can be found across the United States and Canada. They can be found in many bodies of water, preferring those with steeper banks that they can find dens in for shelter as long as there is food available. The dens have underwater entrances that lead to nest chambers lined with leaves, grass, moss, bark, and hair. Otters eat fish, amphibians, and crustaceans, small mammals, mollusks, reptiles, birds and fruits if they can find them. They live to be about 13 years old in the wild.