House Mouse

The house mouse is a small rodent, a mouse, one of the most numerous species of the genus Mus. As a wild animal the house mouse mainly lives associated with humans, causing damage to crops and stored food. The house mouse has been domesticated as the pet or fancy mouse, and as the laboratory mouse which is one of the most important model organisms in biology and medicine. It is by far the most commonly used genetically altered laboratory mammal. House mice have an adult body length (nose to base of tail) of 7.5-10 cm (3.0-3.9 in) and a tail length of 5-10 cm (2.0-3.9 in). The weight is typically 10-25 g (0.4-0.9 oz). They vary in color from white to grey and light brown to black. They have short hair and a light belly. The ears and tail have little hair. The hind feet are short compared to Apodemus mice, only 15-19 mm (0.59-0.75 in) long; the normal gait is a run with a stride of about 4.5 cm (1.8 in), though they can jump up to 45 cm (18 in). The droppings are blackish, about 3 mm (0.12 in) long and have a strong musty smell. The voice is a high-pitched squeak

Scientific Name

Mus musculus

Lifecycle and Habitat

Female house mice have an estrous cycle that is 4-6 days long, with estrus itself lasting less than a day. If several females are held together under crowded conditions they will often not have an estrus at all. If they are then exposed to male urine, they will become estrous after 72 hours.

The gestation period is about 19-21 days, and they give birth to a litter of 3-14 young (average 6-8). One female can have some 5-10 litters per year, so their population can increase very quickly. Breeding occurs throughout the year (however, animals living in the wild don’t reproduce in the colder months, even though they don’t hibernate). The newborn are blind and without fur. Fur starts to grow some three days after birth and the eyes open one to two weeks after birth. Females reach sexual maturity at about 6 weeks and males at about 8 weeks, but both can breed as early as five weeks. House mice usually live under a year in the wild. This is due to a high level of predation and exposure to harsh environments. In protected environments, however, they often live two to three years.

Occurrence

House mice can transmit diseases, and can damage food and food packaging. Some of the diseases the house mouse carries can be deadly: for example, Murine typhus, Rickettsialpox, Tularemia, and the Bubonic plague They can also cause substantial damage when feeding on grain. Generally, rats are more harmful to humans than mice.

The house mouse is a good climber, can jump up to 12 inches high, and can jump down from eight feet. House mice can easily squeeze through holes and gaps wider than ¼-inch. They prefer to nest in dark, secluded areas, where there is little chance of disturbance. Their foraging area is usually small – no more than 20 feet. However, if abundant food is nearby, they nest within four to five feet. House mice nibble on food, preferring items such as seeds and cereals.

Control

The entry hole should be sealed with copper meshing. Within structures, house mice can be controlled effectively by using anticoagulant baits placed in tamper resistant containers. Snap traps and glue traps are also very effective methods of control. Various mousetraps have been developed to catch mice.