Sea otters need to keep clean.
Sea otters spend hours each day grooming their fur. Their fur is their insulation - unlike other marine mammals, sea otters don't have blubber, so their sole way of keeping warm is their fur. A sea otter's fur is made up of an undercoat and longer guard airs. Air around the fur is heated by the sea otter's body heat, and this air in turn keeps the sea otter warm.