The muskrat is the most widespread of North American rodents or microtine, a subfamily of mice. They live in marshes, edges of ponds, lakes, streams, cattails, and rushes but must have enough water depth of flow to prevent substantial freezing. Herbaceous vegetation, both aquatic and terrestrial, is also necessary as their food sources.Generally they have flexible habitat requirements and often coexists in areas used by Beavers. A major difference in appearance with beavers is the tail. Beavers have large dorsally flattened scales over a wide, flat tail. The muskrat tail is flat, but thin and hairless.

The muskrat builds bank dens, dome-shaped lodges, feeding huts, platforms, pushups and canals. They are most active at night but daytime activity is not unusual.