House Mouse

Appearance:
House mice are usually light-brownish to gray in color with large ears and small black eyes.

Size:
Range from 5 to 7 inches in length, including the 3-4 inch tail, and weigh about ½ ounce

Behavior:
A very adaptable animal, the house mouse often lives in close association with humans, along with Roof rats and Norway rats, although mice are more common and more difficult to control. Although house mice usually prefer to eat cereal grains, they are “nibblers” and will eat many types of foods. They have keen senses of taste, smell, hearing, and touch and are active mostly at night, but they can be seen occasionally during daylight hours.

House mice are excellent climbers and can run up any rough vertical surface. They can run horizontally along wire cables or ropes and are able to 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 find their way into homes during the fall or winter months, when outdoor temperatures at night become colder. Droppings, fresh gnaw marks, and tracks indicate areas where mice are active.

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 mating, and they reach reproductive maturity in 6 to 10 weeks. The life span of a mouse is approximately 9 to 12 months.

Habitat:
The House mouse makes its nest from fine shredded paper or other fibrous materials, usually in sheltered locations. House mice have a characteristic musky odor that identifies their presence. They can be found in and around homes and commercial structures, as well as in open fields and agricultural areas. They normally stay near a food source and establish a territory nearby.

Medical and Economic Significance:
House mice consume and contaminate food meant for humans, pets, livestock, or other animals. In addition to causing considerable damage to structures and property, they can contaminate food-preparation surfaces with their feces. They can also transmit pathogens that cause diseases such as salmonellosis, a form of food poisoning.

Control:
Mice can survive in very small areas with limited amounts of food and shelter, so their control can be very challenging. Most buildings in which food is stored, handled, or used will harbor house mice regardless of how sanitary the conditions are. While good sanitation may help control mice, poor sanitation is sure to attract them and will enable them to thrive in greater numbers. If possible, eliminate places where mice can find shelter. If they have few places to hide, rest, or build nests and rear their young, they cannot survive in large numbers.

Exclusion is the most successful and permanent form of house mouse control. Start by sealing and eliminating all gaps and openings larger than ¼ inch (steel wool makes a good temporary plug). Seal cracks in building foundations and around openings for water pipes, vents, and utility cables with metal or concrete. Doors, windows, and screens should fit tightly.

It may be necessary to cover the edges of doors and windows with metal to prevent gnawing. Plastic screening, rubber or vinyl, insulating foam, and wood are unsuitable for sealing or plugging holes since house mice can gnaw through them. Sticky traps and snap traps are effective for controlling small numbers of house mice.