General: Coypu (Myocastor coypus), also known as Nutria, are marsh-rats native to South America and have been introduced widely throughout the world for their fur. Unfortunately, the fur is not very desirable, and they were dumped or escaped captivity. Due to their destructive feeding and burrowing behaviors, they have become pests.

Coypu are recognized by their large size, aquatic behavior, and round tail. Coypu grow to about 2-ft long plus an 18-inch tail and get to about 20 pounds. Coypu can be mistaken for muskrat, which are much smaller and use their laterally flattened tail to swim; and for a beaver, which has a wide, dorso-ventrally flattened tail. Coypu also have a light muzzle and webbed hind feet.

Taxonomy: Class: Mammalia, Order: Rodentia, Family: Myocastoridae.

Head and Body: To about 2-ft long. Fur reddish-brown, long; about the same color on the back and belly.

Tail: To 18-inches long. Little hair; round.

Ears: Very short and rounded.

Weight: to about 20 pounds.

Comments: Coypu are prolific breeders. Females can begin breeding at about 6 weeks of age. Gestation is about 3 weeks, litters to about 10, and they can breed all year.