House mice thrive under a variety of conditions; they are found in and around homes and commercial structures as well as in open fields and agricultural lands. House mice consume and contaminate food meant for humans, pets, livestock, or other animals. In addition, they cause considerable damage to structures and property, and they can transmit pathogens that cause diseases such as salmonellosis, a form of food poisoning.

House mice are small rodents with relatively large ears and small black eyes. They weigh about 1/2 ounce and usually are light brownish to gray in color. An adult is about 5 to 7 inches long, including the 3- to 4-inch tail.

Droppings, fresh gnaw marks, and tracks indicate areas where mice are active. Mouse nests are made from fine shredded paper or other fibrous material, usually in sheltered locations. House mice have a characteristic musky odor that identifies their presence. Mice are active mostly at night, but they can be seen occasionally during daylight hours.

While the house mouse has not been found to be a carrier of hantavirus, other mice have. Most notable are the deer mouse and the white-footed mouse, which sometimes invade cabins and outbuildings in California. The house mouse is distinguished from the deer mouse and the white-footed mouse by its overall gray-colored coat. The other two species have a white underside with a distinct line of demarcation between the dark coloration on top and the white underside. In addition, the tail on the house mouse has almost no fur on it, whereas the tails of the deer mouse and the white-footed mouse are moderately to well furred and are light underneath and dark on top.

Native to Central Asia, the house mouse arrived in North America on ships with settlers from Europe and other points of origin. A very adaptable animal, the house mouse often lives in close association with humans, along with Norway rats and roof rats; however, mice are more common and more difficult to control than rats.