CNN — When sea otters hammer mussel shells against rocks to help open them, they're leaving behind their own archaeological record that can't be compared to any other creature, according to a new ...

Otters are among the few animals known to use tools while feeding. From cracking shellfish with stones to storing favourite ...

Sea otters forage in kelp forests for fish and marine invertebrates. They use a special underarm pouch to carry spare food to the surface. The otters use rocks to smash open hard shells. They have ...