The Heaviest Member of the Weasel Family

Despite being the smallest marine mammal, the sea otter belongs to the weasel family. Instead of relying on blubber for warmth, it keeps cozy with the densest fur in the entire animal kingdom.

You might be surprised to learn that these playful swimmers are distant cousins to badgers and ferrets. While other marine mammals use thick layers of fat to survive icy waters, sea otters depend entirely on their incredible coats, which contain up to one million hairs per square inch. This extreme density traps a layer of air that keeps their skin completely dry. They spend so much time in the water that they can live their entire lives without ever touching land.