The sea otter swims using its flipper-shaped hind feet as paddles. It eats and sleeps while floating on its back. Sea otters often sleep in masses of floating seaweed called kelp. The female carries her baby on her chest as she paddles about on her back. She has one baby, called a pup, at a time.
Sea otters have thick brown fur that traps air and keeps their skin dry.
The fur also insulates them against the cold. Unlike seals and sea lions, sea otters do not have a layer of blubber under their skin. It uses its front paws for grasping and holding, as do some otters that live in fresh water. For information about freshwater otters, see the article on Otter . Sea otters may eat as much as a fifth of their body weight every day.