Muskrats are unique, semi-aquatic rodents named for the musky smell and rat-like appearance. They're known mostly for their destructive burrowing in ponds, streams and dams, but there's more than this to these large wetland-dwelling mammals. Below, learn all about muskrats, including interesting facts and important habits that can help you control their damage.
General Muskrat Facts
Scientific Name: Ondatra zibethicus
Average Size: 16 - 25" long (including an 8-11" tail); 2 - 5 lbs.
Average Lifespan in the Wild: 1 - 3 years
Identifying Features: dense brown fur; rounded body with a long, hairless black tail; webbed hind feet for swimming and smaller front feet for digging; small beady eyes and small ears.
Muskrats are native to North America, with a range that extends from Canada, down to some northern parts of Mexico. They have also been introduced to Northern Europe, Asia, and South America - mainly for their valued pelts.
Muskrats are semi-aquatic mammals that inhabit areas abundant in water like wetlands, ponds, lakes and marshes.
For shelter, muskrats will either dig tunnels or construct lodges, depending on the immediate habitat. In areas with steep banks or dams, muskrats will dig tunnels that begin underwater and lead up above the water level, where the chamber can remain dry. In other areas without steep walls or dams, muskrats build dome-shaped lodges out of nearby vegetation and mud.
Muskrats are omnivores, but they mainly enjoy a plant-based diet consisting of the roots, stems, leaves and fruits of aquatic vegetation. As local plant food becomes scarce, muskrats will feed on small aquatic animals such as insects, fish and amphibians. Freshwater mussels often become a dietary staple in the wintertime.
Some favorite foods include:
Activity: Muskrats are active year-round, and they feed at all times of the day. They are most active at twilight.
Reproduction: Females give birth to 2-3 litters per year, each time yielding an average of 4-8 pups. The size of the litters varies with the seasons, with larger litters being born in spring and summer, and small litters being born in winter. In warmer months, muskrats can give birth to as many as 15 young at once. Newborn muskrats are weaned for about a year before they become independent.
Feeding: Muskrats gather food within their territories and carry it to feeding platforms on which they eat. These feeding platforms are flat, elevated piles of mud and vegetation, which muskrats construct outside of their living dens.
Social Interaction: As monogamous breeders, muskrats live with their mates and their young. They are very territorial - especially during breeding season.
Identify Muskrat Damage
Muskrat damage occurs as a result of their burrowing habits. Oftentimes damage is not very obvious until severe destruction occurs, which is why it's important to understand how to identify muskrat burrows and other warning signs.
Signs of a muskrat's presence or damage include:
- muskrat tracks: four toes in front and five in the back with visible claws; visible tail mark in between prints
- muskrat droppings on dry, elevated surfaces such as stumps, logs, rocks or feeding platforms
- feeding platforms: elevated, flat pads of mud and vegetation
- lodges: piles of mud and aquatic vegetation, up to 8 feet in width and 5 feet tall
- muskrat burrow entrances: holes in backs or dams, about 6-8" in diameter and up to 3 feet below water level
- leaking ponds or dams due to burrowing
- collapsed banks due to extensive burrowing
Muskrats are carriers of some diseases that may be transmitted to humans and/or pets through a bite, drinking contaminated water, or coming into contact with muskrat flesh.
The most serious illnesses include:
- tularemia - via ticks, bites, contact with infected flesh and contaminated water
- leptospirosis - via contaminated, soil or contact with urine
- giardiasis - via contaminated water, contact with/ingestion of waste or ingestion of infected flesh
- rabies - via bites and contact with infected saliva
Muskrats are excellent swimmers, thanks to their webbed back feet, laterally flattened tails, and the ability to hold their breath underwater for 15-20 minutes. They can swim backwards and forwards.
Most of the time muskrats mate underwater.
Muskrat kits are born hairless and blind.
Known to be most valuable for their fur or pelts, muskrats are one of the most trapped animals in history.
Muskrats play important roles in certain ecological systems, as their eating and denning habits create the ideal flat nesting areas for certain birds.