One of the few known nonindigenous mammals (Phylum Chordata, Class Mammalia) is the nutria, Myocastor coypus (pic 102k). It is found in and around fresh and salt water ponds and swamps. Nutrias were initially introduced into North America and farmed for their fur. Since their introduction, some animals have escaped these farms and established localized breeding populations from Texas to Virginia and in the Great Lakes area. Presently, they are considered to be a pest species in some areas, disrupting irrigation systems and destroying native aquatic vegetation and crops. Additionally, by disturbing the balance of the native biota they provide an advantage for non-native plant species to become established.