Adults are about 5.25-7.5 inches with the tail. The tail can take up 2.75-4 inches, relative to the size of the mouse. The fur is smooth and usually dusty gray above and light gray or cream on the belly. The color will vary considerably from area to area regardless of living habits. The muzzle is pointed, eyes are small, incisors are ungrooved, ears are large with very little hair on them, feet short and broad, and a uniformly dark, scaly, semi-naked tail.
Mice are very social. Fleated males and females are compatible, but unrelated males are typically very aggressive toward one another. Social hierarchies with one male dominating lower-ranking males result in the maintenance of territories, which may include a large number of females as well as lower-ranking males, most of which will be related. If food and shelter are plentiful, they may not travel more than 4-5 feet from their nests.
Mice are curious, therefore during the daily territorial patrol, they will explore anything new or changed, and establish new travel routes if needed. Mice are nibblers and eat only small amounts of food at any one time or place. Mice will eat a variety of foods, but seeds are the usual preferred food. The two main meals these house mice eat, are at dusk and dawn. Most moisture is taken from the foods they eat, but will take free standing water when it is available. They prefer sweetened liquids over plain water.
Their preferred nesting sites are dark, secluded places where there is abundant nesting material nearby and little chance of disturbance. Nesting materials include paper products, cotton, packing materials, wall/attic insulation, fabrics, etc. Mice are nocturnal in habit. They require an opening of greater than 1/4 inch to gain entry.
The house mouse is a prolific breeder. They reach sexual maturity in 35 days. Pregnancy lasts an average of 19 days. When the babies are born they are blind and naked except for long whiskers. They are weaned after 3 weeks. The average litter size is anywhere from 5-8, with about 8 litters per year. More than 1 litter may be present in the nest at one time. The life expectancy is normally less than a year, but they may live up to 6 years.
Mice have keen senses, except for eye sight, they cannot see clear beyond 6 inches and are color blind. They are excellent climbers and can swim, but prefer not to swim. They can jump a foot high and can jump down from about 8 feet high without injury. House mice can thrive in cold storage facilities and need to eat 1/10 oz. of dry food and 1/20 oz. of water per day. They will produce 50 droppings per day.
Over a 6-month period, a pair of mice will eat 4 pounds of dog food and produce about 18,000 droppings. The most common way mice transmit disease organisms is by contaminating food with their droppings and/or urine.
Mus musculus Linnaeus