With its sleek round body, short tail, and webbed rear feet, the sea otter is an excellent swimmer. It loves the water, and seldom visits land. It eats, mates, and gives birth at sea. At dusk, the sea otter falls asleep on the water, wrapped in seaweed.

A sea otter may dive 130 feet to look for food. It can quickly catch a crab, a mussel, or a sea urchin with its feet, and bring it back to the surface. Then it swims on its back, so it can use its stomach as a table while it eats! It is the only meat-eater known to use a tool: The sea otter breaks shells with the help of a stone it picks up from the bottom of the ocean. It is always cleaning and smoothing its fur, so it is shiny and thick. The fur must hold as much air as possible to keep the sea otter warm when it is in the cold sea. this clean and fluffy fur is like an insulated blanket for the sea otter. If the fur gets dirty, the otter might die from the cold. Because people once paid a lot for its fur, the sea otter was over overhunted. In the early 1900's, many were killed. But the sea otter is now protected an its numbers have increased.

The sea otter can have young at any time of the year. Mating takes place about every 2 years. The young otter is born in the water. It begins to dive when it's 2 months old but stays near its mother for 6 to 8 months. The mother carries the young otter on her stomach, while she swims on her back.