Muskrats

Muskrats (Ondatra zibethicus) are medium-sized, semi-aquatic rodents native to North America. They belong to the family Cricetidae and the subfamily Arvicolinae. Adults typically weigh about 0.5 to 1.5 kilograms and have a blunt, rounded body, a laterally flattened tail, and dense brown fur. They are proficient swimmers, using their hind feet for propulsion and their tail for steering.

They inhabit wetlands such as rivers, streams, marshes, ponds, and lakes, often along shorelines with emergent vegetation. They construct burrows in banks or build semi-submerged lodges from mud and vegetation; lodges are vented above the waterline and provide shelter. Muskrats are mostly nocturnal or crepuscular and feed on aquatic plants like cattails, reeds, and water lilies, as well as tubers and occasionally invertebrates.

Breeding occurs from spring to fall in temperate regions, with multiple litters per year. Litter sizes typically range from 5 to 10 young. Gestation is about 28 to 30 days, and the young are weaned in 3 to 4 weeks.

Muskrats influence wetland structure by feeding on vegetation and creating shelters that create ponded areas used by other species. They are prey for a variety of predators and can become pests when they damage levees, dikes, crops, or irrigation systems. The species is widely distributed and listed as Least Concern by the IUCN.