Adult body length is usually between 25-40 cm long, with a strong, laterally compressed tail 20-25 cm long. The body is covered in thick, brown waterproof fur. They have partially webbed hind feet and small able hand-like front feet.

Muskrats live in wetlands: ponds, lakes, marshes and river banks, hence the nickname "swamp bunny". They are very good swimmers, using their tail for propulsion in the water. Extensive burrow systems are dug in the ground adjacent to the water with an underwater entrance.

These animals are most active at night or near dawn and dusk. They feed on cattails and other aquatic vegetation, freshwater mussels, frogs, crayfish and small turtles.

Females have 2 to 3 litters of 6 to 8 young. Muskrat populations appear to go through a regular pattern of rise and dramatic decline spread over a 6 to 10 year period.

Muskrats have a unique adaptation that helps with survival. The first is the shape of their nostrils. They look like the numeral seven. The shape of the nostrils allows muskrats to inhale remaining oxygen from recently exhaled breath. This allows for muskrats to swim under water for up to 15 minutes.

Many people who have muskrats in their ponds (especially dammed ponds) dislike muskrats because they burrow into dams and levees, eventually causing structural problems.

Therefore muskrats are hunted year-round to control their numbers, although it is difficult to do so effectively since they breed so rapidly. Often traps are set to catch them, in addition to hunting by .22 caliber rifle.

Traps are set in late autumn to early spring depending upon the length of the trapping season set by each state. Traps such as leg hold traps, body gripping traps or cage traps are placed in run ways or in front of dens to their lodges or bank dens. Apples, carrots or gland lure is used to attract the muskrat to the trap. Leghold traps sizes 1 or 1 1/2 are used or 110 Conibear. Wire is attached to the trap so when the muskrat is caught , it swims out to deeper water and drowns.

In Belgium and The Netherlands, killed animals are sometimes sold to restaurants and served as waterkonijn (water rabbit).