House Mouse

The common house mouse, Mus musculus domesticus, is a small murid rodent, typically weighing 12-30 grams and measuring 6-10 cm in body length with a tail of comparable length. Its fur is generally grey-brown dorsally, often lighter ventrally, and its ears are relatively large and prominent with fine hair. Reproductive maturity is reached astonishingly quickly, often by 5-7 weeks of age, enabling rapid population growth under favorable conditions. Gestation lasts 19-21 days, yielding litters of 5-12 pups, and females can produce 5-10 litters annually, sometimes even more under ideal conditions. Average lifespan is 9-12 months in the wild but can extend to 2-3 years in protected environments, with optimal breeding conditions occurring between 21-32°C and moderate humidity.

House mice are primarily nocturnal or crepuscular, exhibiting peak activity shortly after dusk and before dawn, though they can forage during the day in undisturbed environments or when population pressure is high. They are neophobic towards new objects but exploratory towards novel food sources, often sampling many different items in small quantities, leading to widespread food contamination. Communication occurs through a complex repertoire of ultrasonic vocalizations for courtship and territoriality, as well as scent marking with urine, which conveys information about social status and reproductive state. Their agility allows them to climb rough vertical surfaces, jump up to 30 cm vertically, and squeeze through openings as small as 6 mm in diameter. Public health impacts stem from their role as vectors for pathogens like Salmonella, Hantavirus, and lymphocytic choriomeningitis virus (LCMV), transmitted through droppings, urine, and saliva.