Nutria, Myocastor coypus, were originally introduced to North America from South America because of their potential value as a furbearer. They now occur in much of the United States in marshes, ponds, lakes, and streams. In Utah, the species can occasionally be found in appropriate habitat along the Wasatch Front, in the northern part of the state.

Nutria build nests in burrows or in dense vegetation. Females may produce several litters of three to five young each year. The young develop rapidly, and are able to breed in their first year of life. Nutria are herbivorous, primarily consuming aquatic vegetation; roots are an important part of diet in some locations. The species is mainly active at night.

Nutria appear similar to Utah's native muskrat, but can be distinguished from that species by their round, slightly hairy tails. Muskrat tails are flattened on the sides and hairless.