• The muskrat can regulate blood flow to its limbs and tail; its limbs are usually colder than its body.
• The muskrat’s lips are covered with incisors, isolating them from the mouth cavity. This allows it to bite underwater plants without drowning.
• It has musk glands whose scent is used in perfumery.
• The muskrat is semi-aquatic.

The young muskrat has fur that appears within one week of birth and grows quickly. The species possesses a dense, waterproof coat with a thick undercoat that protects it from cold water. Adult muskrats have webbed feet between their toes to facilitate rapid swimming. They also have a flat tail covered in scales; the tail functions as a rudder while swimming and aids in balancing.