Sea Otters Hold Hands While They Sleep

Sea otters (Enhydra lutris) are one of the ocean's most beloved animals — and one of its most important. They wrap themselves in kelp to sleep, hold hands so they don't drift apart, use rocks to crack open shellfish, and are critical to the health of kelp forest ecosystems.

Why Do Sea Otters Hold Hands?

Sea otters sleep floating on the water's surface. Groups of sea otters (called a raft) hold hands — or wrap themselves in kelp — so they don't drift apart overnight while sleeping. A mother otter will hold her pup on her chest while floating on her back to keep it warm and dry.

Do Sea Otters Use Tools?

Sea otters are one of the few non-primate animals that use tools. They carry a favorite rock in a skin pouch under their armpit and use it to crack open clams, mussels, sea urchins, and abalone on their chest while floating on their back. Some otters use the same rock for years.

Why Are Sea Otters a Keystone Species?

Sea otters eat sea urchins. Without otters, sea urchins multiply and devour kelp forests. Kelp forests are vital ocean ecosystems that support hundreds of species and absorb massive amounts of CO₂. When otters were nearly hunted to extinction for their fur, kelp forests collapsed. Sea otter recovery = kelp forest recovery.

How Do Sea Otters Stay Warm?

Sea otters are the only marine mammals without a blubber layer. Instead, they have the densest fur of any animal — up to 1 million hairs per square inch (humans have 100,000 total). They groom themselves constantly to keep air trapped in their fur, which insulates them from cold water.

Amazing Sea Otter Facts

• Sea otters eat up to 25% of their body weight every day to stay warm.
• Pups are so fluffy they cannot sink — they float like corks.
• Sea otters were nearly driven to extinction in the fur trade — from 300,000 down to 2,000 individuals by 1900.
• They give birth in the water and raise pups entirely at sea.