Mouse Biology
A mouse (plural mice) is a small mammal belonging to the order of rodents. The best known mouse species is the common house mouse (Mus musculus). It is also a popular pet. The American white-footed mouse (Peromyscus leucopus) and the deer mouse (Peromyscus maniculatus) also sometimes live in houses. Another common mouse is the field mouse. This rodent is eaten by large birds such as hawks and eagles. They are known to invade homes for food and occasionally shelter. Although mice may live up to two and a half years in captivity, the average mouse in the wild lives only about four months,[citation needed] primarily owing to heavy predation. Cats, wild dogs, foxes, birds of prey, snakes and even certain kinds of insects have been known to prey heavily upon mice. Nevertheless, because of its remarkable adaptability to almost any environment, and its ability to live commensally with humans, the mouse is regarded to be the second most successful mammalian genus living on Earth today, after humans. Mice can at times be harmful rodents, damaging and eating crops and spreading diseases through their parasites and feces. In western North America, breathing dust that has come in contact with mouse feces has been linked to the deadly hantavirus. The original motivation for the domestication of cats is thought to have been for their predation of mice and their relatives, the rats.
Distribution and habitat
All species of Mus are native to Eurasia and Africa, where they range from lowlands to mountaintops. The five species in the subgenus Pyromys are found in Sri Lanka, India, Pakistan, and mainland Southeast Asia. Much of their range originally consisted of open grasslands or grassy patches in forests.
Reproduction
Breeding onset is at about 50 days of age in both females and males, although females may have their first estrus at 25-40 days. Mice are polyestrous and breed year round; ovulation is spontaneous. The duration of the estrous cycle is 4-5 days and estrus itself lasts about 12 hours, occurring in the evening. Vaginal smears are useful in timed matings to determine the stage of the estrous cycle. Mating is usually nocturnal and may be confirmed by the presence of a copulatory plug in the vagina up to 24 hours post-copulation. The presence of sperm on a vaginal smear is also a reliable indicator of mating.Female mice housed together tend to go into anestrus and do not cycle. If exposed to a male mouse or the pheromones of a male mouse, most of the females will go into estrus in about 72 hours. This synchronization of the estrous cycle is known as the Whitten effect. The exposure of a recently bred mouse to the pheromones of a strange male mouse may prevent implantation (or pseudopregnancy), a phenomenon known as the Bruce effect. The average gestation period is 20 days. A fertile postpartum estrus occurs 14-24 hours following parturition, and simultaneous lactation and gestation prolongs gestation 3-10 days owing to delayed implantation. The average litterinbred mice tend to have longer gestation periods and smaller litters than outbred and hybrid mice. The young are called pups and weigh 0.5–1.5 g (0.018–0.053 oz) at birth, are hairless, and have closed eyelids and ears. Cannibalism is uncommon, but females should not be disturbed during parturition and for at least 2 days postpartum. Pups are weaned at 3 weeks of age; weaning weight is 10–12 g (0.35–0.42 oz). If the postpartum estrus is not utilized, the female resumes cycling 2-5 days postweaning. size is 10-12 during optimum production, but is highly strain dependent. As a general rule, Newborn male mice are distinguished from newborn females by noting the greater anogenital distance and larger genital papilla in the male. This is best accomplished by lifting the tails of littermates and comparing perineums.
As pets
Many people buy mice as companion pets. They can be playful, loving and can grow used to being handled. Pet mice should not be left unsupervised outside as they have many natural predators, including (but not limited to) birds, cats and dogs. Male mice tend to have a stronger odor than the females. Well looked after mice can make ideal pets.
Some benefits of having mice as pets are
- Minimal shedding and allergens
- Entertaining and interactive
- Inexpensive
- Clean (contrary to popular belief)
- Socially self-sufficient when in a group of other mice
- Less likely to bite than other rodent pets
- Relatively intelligent
- Bond well to their owners
- Are playful and attentive
- Short lifespan
- Small and fragile (not as easy to handle as a dog or a cat)
- Defecate and urinate frequently
- Nocturnal
- Frequent eye infections when under stress
- Easily subject to disease when without optimal care
- Frequent reproduction
http://en.wikipedia.org/wiki/Mouse