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. Extensive tunneling into earthen dams may result in water leaks or even in the loss of stored water. Since it is easier to deal with a population of muskrats before they have become established in an area, it pays to watch for signs of these animals and to adopt remedial measures as soon as their presence is noted. Muskrats may be trapped or shot when responsible for property damage. Muskrats are easily trapped.