Muskrats are seldom found far from water. They prefer the still or slow-moving water of marshes, ponds and streams. Muskrats are active year-round and, while usually nocturnal, may move during daylight hours. The muskrat is primarily a vegetarian, feeding mostly on the roots and stems of aquatic plants and, if they occur near water, such items as legumes, grasses, grains, garden crops and apples. Animal food, particularly crayfish and fresh-water mussels, occasionally is eaten.
Muskrats live in houses constructed of vegetation or in burrows dug into banks.
Both houses and burrows have underwater entrances and above-water living chambers. Muskrats breed from early spring until fall, giving birth to several litters of from four to seven young. The young are born naked and helpless in protected nest chambers in houses or bank burrows. Young muskrats grow rapidly and are independent at an early age. Although the feeding habits of muskrats may result in some damage to agricultural or ornamental crops growing near water, the principal cause for concern is the potential damage to earthen water-retaining structures, resulting from muskrat burrowing activities.