The house mouse (Mus musculus) is considered one of the most troublesome and economically important pests in the United States. House mice live and thrive under a variety of conditions in and around homes and farms. House mice consume food meant for humans or pets. They contaminate food-preparation surfaces with their feces, which can contain the bacterium that causes food poisoning (salmonellosis). Their constant gnawing causes damage to structures and property.
Recognizing Mouse Infestations
Droppings, fresh gnawing and tracks indicate areas where mice are active. Mouse nests, made from fine shredded paper or other fibrous material, are often found in sheltered locations. House mice have a characteristic musky odor that identifies their presence. Mice are occasionally seen during daylight hours.
House Mouse Facts
House mice are gray or brown rodents with relatively large ears and small eyes. An adult weighs about 1/2 ounce and is about 5 1/2 to 7 1/2 inches long, including the 3 to 4 inch tail.
Although house mice usually feed on cereal grains, they will eat many kinds of food. They eat often, nibbling bits of food here and there. Mice have keen senses of taste, hearing, smell and touch. They are excellent climbers and can run up any rough vertical surface. They will run horizontally along wire cables or ropes and can jump up 13 inches from the floor onto a flat surface. They can slip through a crack that a pencil will fit into (sightly larger than 1/4 inch in diameter).
In a single year, a female may have five to 10 litters of usually five or six young each. Young are born 19 to 21 days after mating, and they are mature in six to 10 weeks. The life span of a mouse is about nine to 12 months.
Prevention and Control
Effective mouse control involves sanitation, mouse proof construction and population reduction. The first two are useful as preventive measures. When a mouse infestation already exists, some form of population reduction is almost always necessary. Reduction techniques include trapping and poisoning.
Mice can survive in very small areas with limited amounts of food and shelter. Consequently, no matter how good the sanitation, most buildings in which food is stored, handled or used will support house mice if not mouse-proofed. Although good sanitation will seldom eliminate mice, poor sanitation is sure to attract them and will permit them to thrive in greater numbers. Good sanitation will also reduce food and shelter for existing mice and in turn make baits and traps more effective. Pay particular attention to eliminating places where mice can find shelter. If they have few places to rest, hide or build nests and rear young, they cannot survive in large numbers.
The most successful and permanent form of house mouse control is to "build them out" by eliminating all openings through which they can enter a structure. All places where food is stored, processed or used should be made mouse-proof. Dried grain and meat products should be stored in glass jars, metal canisters or other resealable airtight containers.
Seal any openings larger than 1/4 inch to exclude mice. Steel wool mixed with caulking compound makes a good plug. Patching material needs to be smooth on the surface to prevent mice from pulling out or chewing through the patching compound. Seal cracks and openings in building foundations and openings for water pipes, vents and utilities with metal or concrete. Doors, windows and screens should fit tightly. It may be necessary to cover the edges with metal to prevent gnawing. Plastic sheeting or screen, wood, rubber or other gnawable materials are unsuitable for plugging holes used by mice.