Tell Me About Mice

The house mouse is all too familiar to most. The house mouse is just about what you’d expect a mouse to be – small (two to three inches), gray-brown, somewhat protruding eyes; large sparsely harried ears and an almost naked tail as long as or longer than its body.

House mice live mostly around buildings, moving into weedy fields and burrow pits in the summer and into buildings (homes, barns, and sheds) in the winter. The entire area occupied by a mouse during its lifetime may be less than the size of an average room.

Mouse Signs

When mice are present, they can and will contaminate food with urine and feces.


When mice are present, tracks, including footprints or tail marks, may be seen on dusty surfaces or in mud. A tracking patch made of flour, rolled smooth with a cylindrical object, can be placed in pathways overnight to determine if mice are present. Droppings are often found and they are rod-shaped, about 1/4 to 1/3 inches long and one of the best indicators of mice.


Mice may also cause considerable property damage by gnawing wood, paper, cloth, books, and insulation on wiring. Nests may be found in hidden places, such as little-used drawers or cabinets, and are made from loose assemblies of paper, cloth, twine, and other material.


Sounds such as gnawing, climbing in walls, running across the upper surface of ceilings, and squeaks are common where mice are present.

Nests are frequently found when cleaning garages, closets, attics, basements, and outbuildings. The nests consist of fine shredded fibrous materials.

Damage Prevention and Control Methods

Effective prevention and control of house mouse damage involves three aspects: rodent-proof construction, sanitation, and population reduction by means of traps, toxicants, or fumigants. The first two are useful as preventive measures, but when a house mouse infestation already exists, some form of population reduction is almost always necessary.

Habitat Modification

The removal of food sources through proper sanitary techniques is essential. Attention should be paid to both obvious and not-so-obvious sources of food. A small amount of spillage from birdseed stored in a garage or shed can be more than enough to sustain a mouse. Dry pet food left in the garage overnight or next to an appliance behind which there is access from the wall will attract mice. Appliances also offer security from which foraging trips into the kitchen can be made to pick up the tiny amounts of spilled food that makes a meal.

Household food items that are accessible to mice should be stored in metal or plastic containers. Removing weeds and trimming a vegetation-free perimeter for at least 18 inches out from the foundation of the house or building to be protected can eliminate protective cover. This procedure allows better recognition of entry points as well. Pets should be fed indoors and uneaten food picked up where mice are known to be a problem. For additional information please refer to the Colorado State University Extension Office website.