In most species, the webbing is extensive enough to help the animals swim swiftly. Otters, like beavers and muskrats, have long coarse guard hairs that cover and protect the short, thick underfur. This underfur traps air and keeps the otter's skin dry. In some species, a layer of fat under the skin insulates the otter from the cold. An otter's fur varies in color from brownish-gray to dark brown when dry, and appears darker when wet.
Otters often use their paws to handle objects.
They hold and play skillfully with such things as stones and small shellfish. Some African and Asian species that have only a little webbing between their toes can use the toes like fingers. Such clawless and small-clawed otters handle food in much the same way as raccoons. These otters feed on shellfish that live in shallow water. All otters have claws.