A water rat is specifically adapted for hunting in and living near water. There are 18 unrelated species of these rodents, found on several continents. Muskrats, water voles, rakalis, and golden-bellied water rats all fall under this classification.
While all rats are in the family muridae, they are not all closely related. Some species known as water rats are not actually rats, but all are rodents. Many are mistaken for other animals, such as beavers or platypus. Most are carnivores, but some are not. Animals known as water rats vary widely in size and habitat.
The water vole is indigenous to Europe. Water voles are about six to eight inches (15.24 to 20.32 cm) long, not including their tails, and they weigh about six to ten ounces (170 to 283.5 grams). Their fur is brown or black, and they have short, hairy tails. Water voles have small ears with skin flaps, which close to prevent water entering. Unlike most types of water rat, water voles are herbivores.
Rakali are larger, at 9 to 15 inches (22.86 to 38.1 cm) in length, and 12 to 45 ounces (340 to 1275 grams), with a long broad tail measuring 9.5 to 13.5 inches (24.2 to 34.5 cm). This mammal is native to Australia, and burrows into the banks of lakes and rivers. Rakali have flat heads, long noses, and webbed hind feet. Their fur is brown or black, with a white belly. Diet for the rakali is varied and includes insects, fish, shellfish, birds, and eggs.
Muskrats are in the same family as beavers. They live in burrows, swamps, and marshes. Muskrats are large and plump, usually about 12 inches (30.5 cm) long and weigh up to 63 ounces (1.78 kg) as adults. They have webbed hind feet and glossy brown fur. Communication is done by releasing a substance called musk from their glands because their hearing, vision, and smell are poor.
The golden-bellied water rat is found in Australia, Tanzania, and New Guinea. They live near lakes and rivers, eating fish and shellfish. Their fur is brown or gray, with white-tipped tails and, occasionally, lighter underbellies. The golden-bellied water rat is about 30 ounces (850.5 grams) fully grown. Unlike other water rats their fur is not waterproof, but all four feet are webbed.
Earless water rats are found in New Guinea. Their hind feet are long and webbed, and their ears are completely hidden. The waterproof fur of the earless water rat is brown on the back and white on the belly. Their long tails are tipped with white. They are six to nine inches (15.24 to 22.86 cm) long, and weigh about six ounces (170 grams).