Seals are sleek-bodied and barrel-shaped. Their bodies are well adapted to the aquatic habitat where they spend most of their lives. Pinnipeds have flippers for hands, big bulky bodies, doggish faces, and big eyes. Unlike cetaceans, pinnipeds have their noses on their faces, and each nostril of the nose closes when the pinniped goes underwater. Like cetaceans, pinnipeds have a thick layer of blubber (fat) just under their skin: this blubber keeps them warm in cold waters and keeps them fed during times when food is not easily found. When they cannot find food, they live off the fat in the blubber.