As one of the few animals that uses tools, sea otters can feed on mollusks like clams and abalone, using a rock to break open their shells. When sea otters are underwater foraging for food, they make use of the loose skin under their armpits, using the area as pockets to store food as they continue their search. While in the water, otters need to make sure they don’t drift too far from their group when sleeping. Wrapping themselves in kelp helps them stay in one place, but they have also been known to hold hands to keep their offspring or friends close by when sleeping.