House mice are small rodents with relatively large ears and small, black eyes. They weigh about 1/2 ounce and usually are light brownish to gray.  An adult is about 5 to 7 inches long, including the 3- to 4-inch tail.

In a single year, a female may have 5 to 10 litters of about 5 or 6 young.  Young are born 19 to 21 days after conception, and they reach reproductive maturity in 6 to 10 weeks.  The life span of a mouse is usually 9 to 12 months.

Droppings, fresh gnaw marks, and tracks indicate areas where mice are active.  Mouse nests are made from finely shredded paper or other fiberous material, usually in sheltered locations.  House mice have a characteristic musky odor that reveals their presence. Mice are active mostly at night, but they can be seen occasionally during daylight hours.

Although house mice usually prefer to eat cereal grains, they are nibblers and will sample many different foods.  Mice have a keen sense of taste, hearing, smell, and touch.  They also are excellent climbers and can run up any rough vertical surface.  They will run horizontally along wire cables or ropes and can jump up to 12 inches from the floor onto a flat surface.  Mice can squeeze through openings slightly larger than 1/4 inch across.  House mice frequently enter homes in autumn, when outdoor temperatures at night become colder.

Prevention Tips

Regular removal of debris and control of weeds from   around structures will reduce the amount of shelter available to mice.

Keep the perimeter of buildings and other structures clean of weeds and debris (including stacked lumber, firewood, and other stored materials) to discourage rodent activity and to allow easier detection of rodent sign.

Store bulk foods in rodent-proof containers.

Repair all holes and cracks around exterior larger than a 1/4 inch, using steel mesh.