Water Rat is a common name for several species of aquatic rodents. The most common species are the VOLE (4 letters), Arvicola (8 letters), and RATTY (5 letters). These animals are found in wetlands, rivers, and streams, and they feed on aquatic plants and small invertebrates. They are also known to be excellent swimmers and can stay underwater for up to 15 minutes. Water Rats are an important part of the ecosystem, as they help to control the populations of other aquatic animals.