otters commonly wrap crabs in strands of kelp to immobilize them and leave the wrapped crabs on the chest while the otter eats other kinds of collected prey from the ocean bottom. sea otters are familiar with kelp as a wrapping agent because they wrap themselves in kelp to remain in one location at the surface during periods of rest, or during sleeping. mother otters also wrap their offspring in kelp when they cannot rest the pups on their chests.