What’s the smallest marine mammal? What animal eats lying on its back? The sea otter, of course.

Though related to skunks and weasels which live on land, otters spend most of their time in the water. Their sleek, streamlined bodies and webbed feet make them excellent swimmers. Sea otters have the densest fur of any animal, and they have two layers of it that help them stay warm in cold water.

Sea otters are mammals, and therefore breathe air. However, otters can hold their breath for deep dives to the ocean floor. Their favorite foods are often found buried in the sand or nestled in rocks. They eat shellfish, spiny sea urchins, crabs, shrimp and small fishes. Otters eat a great deal because their bodies burn energy quickly. Sea otters are known for their unique style of eating. They usually lie on their back and crack open shells on their chest.

California sea otters are a threatened species. They were once hunted for their fur. Now, their worst enemies are oil spills and other pollution.

These playful animals live in coastal areas of the Pacific Ocean, where they float and somersault in the kelp forests. (Kelp is a type of large seaweed.) Otters spend their time playing and looking for food. The kelp forest provides them food and protection. A mother otter may wrap her baby in kelp to keep it from floating away when she dives for food. Sometimes sea otters have to swim through dark or murky water to find food. Otters have very long whiskers, which they use to “feel their way” and help them find food.

Do it yourself

Make your own “otter whiskers” and use them to find objects underwater.


  • Two-three twist-ties
  • Four-six pipe cleaners (or pieces of uncooked spaghetti cut in half)
  • Large tray or tub of water
  • Several objects that can be submerged in water, like plastic toys or seashells


  1. Start by making the whiskers. Using twist-ties, fasten the pipe cleaners or spaghetti together. The pipe cleaners or spaghetti should run in the same direction, but be separated, to look like whiskers.
  2. Place a couple of the objects in the tray/tub of water, fairly spread apart.
  3. Roll up your sleeves and grasp the center of the whiskers between your thumb and index finger. Guide the whiskers through the water until you find the objects. Can you tell when the whiskers touch the objects? If you were a sea otter, these objects might be a meal!
  4. Next, either close your eyes or turn the lights off in the room. Can you use the whiskers to find the objects?
  5. Add many different kinds of objects to the tray or tub of water. Try a shell, a rubber ball, a pencil and a dish cloth. Can you tell which is which? This exercise should help you appreciate this skill that the sea otter has perfected.