House Mouse
Mus musculus

How did it get here?

Originating in Asia, the house mouse traveled to North America on the ships of early setters from Europe. Along with the Norway rat and black rat, it is known as an “old world rodent."

How to spot

House mice are most likely to be inside when it’s cold outside. Look for the following signs in cupboards, closets, or storage areas: ball-shaped nests made from shredded paper or other fibers, droppings, gnaw marks, and musky odor.
The mouse is 6 to 7 inches long with its tail. The fur on its back and belly is brownish to gray. The tail is long, with scales in circular rows. The large ears lack fur. The mouse weighs ½ ounce to 1 ounce.

Habitat characteristics

Mus musculus lives in houses, groceries, factories, grain storage buildings, old fields, pastures, and roadsides. It prefers hidden spots near food.

Life Cycle

The house mouse has a life span of 9 to 12 months. It is able to reproduce when it is 6 to 10 weeks old. The young are born 19 to 23 days after mating. The mouse produces four to 10 litters a year, with 5 to 7 young in each litter.

Look-alikes and how to distinguish

• White-footed mouse Peromyscus leucopus—white feet and white or light-colored belly and chest; tail dark on top and light on bottom; larger ears and eyes; lacks odor.
• Meadow vole Microtus sp.—compact and stocky; short legs and tail; small ears; doesn't climb.

Why is this animal a problem?

• House mice are very destructive to property. They burrow under buildings and undermine structures; chew furniture, walls, insulation, clothing, etc.; chew electrical wires, which can start fires; and gnaw wood, which can weaken wooden structures.
• House mice destroy valuable food sources, especially stored grain. In six months, one pair of mice can eat 4 pounds of food and leave 18,000 droppings, or feces.
• House mice can transmit diseases to humans, including bacterial food poisoning, tapeworms and roundworms, and rickettsial pox. They also can transmit dysentery to swine.

Management approaches

• Eliminate habitat by cleaning up trash and debris around property.
• Store pantry items, bird seed, etc. in gnaw-proof containers.
• Close all possible entry points with metal sheeting.
• Bait live traps with peanut butter. This will allow you to catch and identify a mouse without killing it. For more information, click here and here.
• Encourage natural predators like barn owls. Click here or here.

Other resources

Florida Fish and Wildlife Conservation Commission
Species account

University of Nebraska-Lincoln, Institute of Agriculture and Natural Resources
Article: "Controlling House Mice"

Animal Diversity Web, University of Michigan Museum of Zoology
Species account and photos