Common Muskrat

Ondatra zibethicus
Family

Cricetidae (New World rats and mice) in the order Rodentia

Description

The common muskrat is a medium-sized mammal that has short front legs with small feet, stronger hind legs with large feet, and a vertically flattened, scaly tail that is slightly shorter than the combined length of head and body. The hind feet are partially webbed. The back is blackish brown, and the sides are lighter brown with a reddish tinge; the underparts are still lighter, shading to white on the throat. Their musk glands produce a mild and inoffensive odor.

Size

Total length: 16–25 inches; tail length: 7–11 inches; weight: 1½–4 pounds.

muskrat_11-15-11.jpg

Image of muskrat
Muskrat
This muskrat is surrounded by the floating aquatic plant duckweed.

Muskrat

Muskrat
Muskrat
Muskrat swimming in frog pond. Note the tail shape.

FG-0030_Muskrat.mp4

Video of a muskrat in the wild.

Muskrat

Muskrat
Muskrat
Muskrat swimming amid duckweed in frog pond

Muskrat

Muskrat
Muskrat
Muskrat eating aquatic a crayfish in a frog pond.
Habitat and conservation

Muskrats are semiaquatic, living in marshes, sloughs, streams, rivers, ponds, and lakes. Here they dig homes in a stream or pond bank or build large houses out of vegetation in the shallow water. The nest, or den, is reached by means of a tunnel that usually opens under water. In Missouri, the most important management measure is to regulate the harvest. Where muskrats are too numerous, trapping is the most satisfactory means of control.

Foods

In marshy areas, muskrats eat rootstocks and stems of cattail and three-square bulrush and the seeds of lotus. In other areas of the state, white clover, corn, and bluegrass are preferred. Muskrats living along Ozark streams eat freshwater clams, snails, crayfish, fish, frogs, and aquatic plants.

image of Muskrat Distribution Map
Distribution in Missouri

Statewide.

Status

Common.

Life cycle

Breeding occurs from late winter to mid-September, with 3 peaks, at the ends of March, April, and May. Pregnancy averages 28 days; usually 2 or 3 litters are produced annually by a female. The litters usually contain 4–7 young, which are born blind and nearly helpless and naked. After a week they have coarse gray-brown fur. In another week, their eyes open and they start to swim and dive. At 3 to 4 weeks of age, they are weaned. Most breed for the first time in the following spring.

Human connections

Muskrat pelts are common on the commercial market; almost all is used in the manufacture of women's coats. The fur is durable; the skin makes strong leather and takes dye well.

The flesh of muskrats tastes gamey.

Dried musk is used in making perfumes and in preparing scent for trapping animals.

In old-time Ozark dialect, the "sk" sound in words like "muskrat" was softened to a "sh" sound, and it was common for early American hunters and trappers to pronounce the word as if it were spelled "mushrat." Linguists say this is an example of how Elizabethan English, brought to America by its early colonists, survived in Ozark dialect.

Ecosystem connections

As omnivores, muskrats help control populations of both the plants and the small animals they consume.

The dens, mounds, tunnels, and canals they construct become habitat for other organisms to use.

Muskrats and their young are preyed upon by many predators.

Signs & Tracks

Front track:

  • 1½ inches long
  • 4 toes usually show; thumb is small but is also sometimes visible
  • Narrower than hind track.

Hind track:

  • 3½ inches long
  • 5 toes.

Other notes:

  • Muskrat are common in marshes, ponds, streams, and similar aquatic places.
  • The dragging tail sometimes leaves tracks.
  • Look for plant cuttings and scat at the water’s edge.
  • Muskrat houses are mounds of plant cuttings and mud, built in shallow water. These can be confused with beaver lodges but are made of nonwoody vegetation.
  • Muskrat also live in bank dens.
Illustration of common muskrat tracks