Muskrats are common semi-aquatic rodents found across North America and parts of Eurasia, inhabiting wetlands, ponds, lakes, and slow-moving streams. Their daily and seasonal behaviors are finely tuned to their environment.
Daily Activity Patterns
Muskrats are primarily crepuscular, with peak activity occurring during the twilight hours of dawn and dusk. These low-light conditions offer concealment for foraging and movement. During these times, muskrats are often seen swimming, searching for food, and maintaining their lodges or burrows. They are adept swimmers, using partially webbed hind feet for propulsion and flattened tails as rudders.
While primarily crepuscular, muskrats also exhibit nocturnal activity. They may forage throughout the night, gathering vegetation and transporting it back to their homes or feeding platforms. Occasionally, diurnal activity is observed, particularly during periods of high food demand or the breeding season. Even during daylight hours, muskrats are busy with home construction, foraging, and raising young.
Seasonal Activity Shifts
Muskrat activity and behaviors change seasonally. During winter, muskrats do not hibernate and remain active year-round. Surface activity is reduced, with more time spent within insulated lodges or burrows, which often have underwater entrances. They continue to forage under the ice, utilizing “push-ups” – small shelters built on the ice over an opening – to breathe and consume vegetation.
Spring brings increased activity with the breeding season. Muskrats become more active at dawn and dusk, engaging in territorial defense and searching for mates or new territories. Throughout the summer, activity remains consistent, supported by abundant food and the demands of raising multiple litters. Young muskrats are weaned quickly and become independent within about a month.
Autumn marks preparation for winter. Muskrats increase foraging efforts to build up fat reserves. Extensive construction and repair of lodges and burrows also occurs for winter occupancy. Some muskrats may store vegetation for winter use, though they generally do not cache large amounts of food like other rodents.
Factors Influencing Activity
Several factors shape muskrat activity. Predation risk drives their crepuscular and nocturnal habits. Low-light activity reduces exposure to predators like hawks, eagles, foxes, and coyotes. Mink, raccoons, owls, and large fish also prey on muskrats, influencing their movements both in and out of the water.
Food availability influences foraging times and intensity. Muskrats primarily consume aquatic vegetation such as cattails, sedges, and water lilies. When plant foods are abundant, they may feed more frequently. If vegetation becomes scarce, muskrats may expand their diet to include small aquatic animals like mussels, crayfish, or frogs, altering their foraging patterns.
Temperature and weather influence muskrat activity. During extreme cold in winter, muskrats spend more time inside insulated lodges or burrows to conserve warmth. They can navigate and forage under ice, but prolonged exposure to very cold water can lead to body temperature drops. Conversely, in very hot summer conditions, muskrats may seek shelter during the warmest parts of the day to avoid overheating. Ice cover can restrict their movement, forcing them to deeper water or limited foraging.
The breeding season significantly increases muskrat activity. Finding mates and establishing territories leads to more frequent movements and interactions, including territorial disputes. Females can produce multiple litters per year, with the number and size of litters varying seasonally and geographically. This contributes to heightened activity during spring and summer.
Human disturbance modifies muskrat behavior. In areas with frequent human presence, such as boating activity or shoreline development, muskrats may become more nocturnal to avoid encounters. While generally shy, sustained human activity can alter their natural rhythms, causing them to adjust routines to minimize interaction.