The house mouse is the most troublesome, and economically important rodent in the United States. Except for the spread of food poisoning, house mice are not as important as rats as carriers of disease. However, mice can transmit diseases such as salmonellosis, meningitis, leptospirosis, rat-bite fever, ringworm, and dermatitis. Mice can transmit diseases by contaminating food with their urine, and feces. The house mouse produces about 70 droppings per day.
The adult house mouse weighs about one ounce, and is 2 ½ to 4 inches long, not counting the tail. The tail is nearly hairless and is about as long as the head and body combined. Adults vary in color from light brown to dark gray. Most are dusky gray or medium brown over most of their bodies, except for the belly, which may be a lighter shade. Mice have moderately large ears for their body size, and their feet are small in proportion to their body.
House mice can breed all year long under optimum conditions. Females may produce as many as ten litters a year. Newborn mice are nearly hairless, and their eyes are closed. At the end of two weeks, they are covered with hair, and their eyes are open. At three weeks the young begin to take short trips away from the nest.
House mice prefer cereals but will eat a variety of food. Mice get much of their water from their food but will drink water if it’s available. Mice are nibblers and feed twenty or more times during the evening. They feed mainly at dusk, and just before dawn. They seldom travel more than thirty feet from their nest, and when food is nearby may restrict their activity to a few feet. Mice can squeeze through a very small hole (reportedly 1/4 inch). They are very curious and like to investigate new objects.
Mice in the home can be controlled with good sanitation, elimination of the food supply, mouse-proofing, and extermination using traps or baits. The best sanitation will not eliminate house mice, however, it will increase the effectiveness of baits and traps by reducing competing food. Their food source can be removed by storing food in mouse-proof containers. Food should also be stored off of the floor, and away from walls. Homes can be mouse-proofed by plugging holes in foundation walls, sealing holes around pipes, vents, etc., and caulking doors and windows. Mice already present in a building must be killed. Mice can be trapped with spring traps, multiple-catch traps, and glue boards, or killed using rodenticides.
Mouse traps must be set in the right places, and in sufficient numbers. Mice have a small territory. If mice are seen at different locations in a building it means that traps will have to be set wherever they have been sighted. Traps should be set in places where they spend a lot of time (look for large numbers of droppings), and along their runways. Since mice like to investigate new things, moving traps and other objects around can increase the effectiveness of traps. The same procedures apply to baiting.
Public Health regulates mouse infestations within rental properties only under Public Health Nuisance Regulation 2-93, Section 7D. In cases where mice have inhabited a rental property, Public Health can order the property owner to initiate control measures within the structure. Public Health does not regulate mouse harborage or mouse populations in the outdoor environment.