It has thick brown fur, short legs and weighs around 18 pounds. It can grow almost three feet long. The otter has stiff whiskers around its nose and a long tail. Where do river otters live? River otters live by streams, ponds, lakes and marshes in North America. They sleep during the day in a den or among a bunch of weeds. What do river otters eat? Otters eat fish, crayfish, water insects, frogs, turtles and birds. More facts about the otter: - Otters are excellent swimmers. They can swim up to 7 miles per hour. - A lynx or other big cat is a predator. - In the winter river otters spend a lot of time under the snow and ice. - The river otter takes tiny bites of food. Its throat is narrow so it cannot swallow big chunks of food. - A river otter can outrun a person. - Its fur is waterproof. - They make a sound that sounds like snorting or coughing. - The river otter can stay underwater for around four minutes.