House Mouse

Small holes, cracks and crevices around your building are key entry points for the house mouse as they can squeeze through a hole the size of a dime.

Nesting Habits

Mice are very social. Related males and females are friendly with each other, whereas unrelated males tend to be aggressive toward each other. Often one male will dominate lower-ranking males to maintain territories. Those territories can also include many female mice, most of which will be related. Mature mice show aggression to all unfamiliar mice and will mark their territory with urine.

Mice are inquisitive, exploring anything new or changed during daily territorial patrol.

They eat only small amounts, usually twice daily – just before dawn and dusk – with many other “mini” feeding times in between. They get most of their moisture from their food, but will at times drink water when available.

The house mouse prefers dark, secluded places with abundant nesting materials such as paper products, cotton, packing materials, insulation, fabrics, etc. If sufficient food, shelter and resources are available, mice may stay within a few feet of their nest.

House mice are nocturnal and only need a quarter of an inch (6 millimeters) opening to gain entry. They don’t hibernate, so they seek shelter during cooler months and are attracted to warm odors and temperatures seeping from door thresholds, utility line entrances, etc. Entrances marked by other mice are more attractive to them.


Not only a nuisance pest, house mice are very destructive. They gnaw on many different products and materials, including electrical wiring. Also, everywhere they go or feed (nibble) is contaminated by mouse urine and droppings. Food contamination, especially Salmonella, is a major food safety concern.

Adult head and body measure 2 ½-3 ¾ inches (6.5-9.5 centimeters), tail length 2 ¾-4 inches (7-10.2 centimeters) and weigh 0.5-1.1 ounces (12-30 grams).

Smooth fur colored dusty gray on top of body and light gray or cream on belly. Fur color can vary according to region.

Throughout the world.

Many kinds of food, but seeds and insects are preferred.

Prolific breeders, house mice average eight litters per year with six young per litter. They reach sexual maturity in 35 days and mate at six to 10 weeks old. Pregnancy can last 18-21 days, and females can carry a new litter once every 40-50 days. Life expectancy is less than a year.

Despite only being able to see 6 inches (15 centimeters) in front of them, their other senses are quite sharp. They are excellent climbers with the ability to run up most roughened walls. They can jump 12 inches (30.5 centimeters) high and can jump down from 8 feet (2.5 meters) without injury.

Control is difficult when mice are out of control. Occasionally in some small areas, there will be a population explosion where thousands of mice will be present.