Water voles have a rounded, blunt snout and a plump little face with tiny, almost hidden ears, along with a long, fur-covered tail. Their coat is usually a rich chestnut brown, though many Scottish animals are much darker, sometimes almost black. The dense fur traps air to help keep them warm while swimming, and they have small skin flaps at the ears to stop water getting in. Water voles are plant-eaters, feeding on a wide range of waterside vegetation and consuming up to 80% of their body weight each day.