Its long tail is thick near its body and tapered to a point. The otter weighs 5 to 14 km and the male is usually about a third larger than the female. Because they are so shy of people, no one knows how many river otters still live in Ontario. It is different from the sea otter, a close relative, because it lives inland, makes its den on shore, and hunts on land as well as in the water. It swims quickly through the water catching fish, slides and runs across wet and dry land catching small animals.
People like to watch it slide down banks at zoos.
Its main diet is fish, including minnows, sculpins, perch, sunfish, catfish, and occasionally trout. It catches its food with a sideways snap of its jaws. Otters living on the shores of the Great Lakes also eat lampreys. Lampreys are eel-like fish that suck blood from sports fish. The otter eats clams, crayfish, frogs, toads, snakes, beetles, snails, worms, and bird eggs.