House Mice

Identification & Appearance

House mice (Mus musculus) are the most common rodent pests in homes. Body length 7-10cm, tail roughly equal to body length. Back is yellowish-brown to gray-brown; belly is gray-white. They are small and slender with a pointed snout, relatively large round ears, and a tail with ring-like scales. House mice are curious and explore new objects readily, traveling along walls and edges (thigmotaxis). Their home range is small, typically 3-9 meters. They eat 3-4 grams daily, preferring grains, seeds, and nuts but also consuming insects and meat.

Habits & Hiding Places

House mice are nocturnal, most active at dusk and dawn. In heated indoor environments, they are active and breed year-round. Their home range is just 3-9 meters around the nest. They follow walls and edges, leaving urine and feces trails containing pheromones. They typically stay at ground level or low elevations; climbing ability is moderate. Their most remarkable ability: they can squeeze through openings as small as 6mm.

Health Risks & Damage

1. They gnaw electrical wiring, insulation, wood, and plastics, causing electrical fires and property damage.;
2. They transmit diseases including Salmonella, leptospirosis, lymphocytic choriomeningitis virus (LCMV), and hantavirus.;
3. Urine, feces, and shed dander are potent allergens triggering asthma.;
4. Reproduction is explosive: females produce 5-10 litters per year, 4-16 pups per litter. Young reach sexual maturity at 6-10 weeks. Uncontrolled populations rapidly explode.;
5. They chew through food packaging, contaminating stored food with feces and urine.

Season & Region

Cosmopolitan; year-round indoor activity. More frequently enters buildings to seek food and shelter as weather cools in autumn–winter. Small home range; typically active at ground level or low elevations.