[n. mous; v. mouz]
mouse, name applied to numerous species of small rodents, often having soft gray or brown fur, long hairless tails, and large ears. The chief distinction between these animals and the variety of rodents called rats is in size: mice are usually smaller. Many small rodents are adapted for leaping or hopping and are named accordingly, e.g., the North American kangaroo rat and Asian jumping mouse.

Types of Mice

Most, but not all, of the rodents called mice are members of the rodent subclass Myomorpha, or mouselike rodents. The approximately 1,100 species in this enormous group are classified in several families. The Old World family Muridae includes the now ubiquitous house mouse, as well as a great variety of wild-living Old World species, including the Old World field mouse, the tiny European harvest mouse (Micromys minutus) and the African tree mice. The cosmopolitan family Cricetidae includes the native New World mice, such as the deer mouse, American harvest mouse (Reithrodontomys), the carnivorous grasshopper mouse, the South American field mice, the pack rat, and the rice rat; it also includes the various Old and New World species of vole, hamster, lemming, muskrat, and gerbil. Still other families of the Myomorpha include the dormouse, jumping mouse, and jerboa. The pocket mouse and the kangaroo rats and mice are members of the suborder Sciuromorpha, or squirrellike rodents.

House Mouse

The house mouse, Mus musculus, found throughout the world, is the most familiar of the mice; many of its races live commensally with humans and are serious pests, while others live in the wild. It usually measures about 6 in. (15 cm) long and weighs under 1 oz (28 grams). It has gray to brown fur, large rounded ears, a pointed muzzle, and a naked scaley tail. An omnivorous feeder, it causes great destruction and contamination of food supplies. Its nests are built of available chewable materials, such as clothing and paper. It may carry human diseases, such as typhoid and spotted fever. Females produce litters of four to eight young after a gestation period of three weeks; under favorable conditions they breed throughout the year. The young mature in two months. House mice, particularly albino strains, are extensively used in biological and medical experimentation and are also sometimes kept as pets.

Field Mouse

Field mouse is a name applied to various wild-living mice in different parts of the world. The Old World field mice are species of the genus Apodemus, closely related to the house mouse and found throughout Eurasia and North Africa. The widely distributed long-tailed field mouse, Apodemus sylvaticus, is a nocturnal, burrowing creature that prefers succulent plant food and frequently invades gardens and houses. In North America the name field mouse (or meadow mouse) is applied to voles. South American field mice belong to the genus Akodon, with about sixty species distributed among a wide variety of habitats, including human dwellings. Most of these resemble long-tailed voles. The name tree mouse is likewise applied to various arboreal mice and voles in different parts of the world.


Mice are classified in the phylum Chordata, subphylum Vertebrata, class Mammalia, order Rodentia.

or wood mouse

In general, any mouse that normally lives in fields; more strictly, any of about seven species of small, long-tailed mice in the genus Apodemus (family Muridae). Field mice in this genus are found in fields, woodlands, and mountain meadows in the warm and temperate parts of Eurasia. They are grayish or light or reddish brown and are 2–5 in. (6–12 cm) long excluding the tail. They generally live in burrows and build nests of grass and other plants. They eat seeds, roots, and other plant material, occasionally damaging crops or young trees.

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Any of about 30 species of nocturnal North American rodents constituting the genus Perognathus (family Heteromyidae), having fur-lined, external cheek pouches that open alongside the mouth. Pocket mice are yellowish brown to dark gray and are 2.5–5 in. (6–13 cm) long, excluding a tail of about the same length. They are usually solitary and inhabit dry and desert regions. They carry food (mainly seeds) in their pouches and store it in their burrows. Spiny pocket mice (most in the genera Liomys and Heteromys; family Heteromyidae), found from Mexico through Central America, are gray, brown, or black nocturnal burrowers that inhabit wet, forested regions as well as dry country.

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or mouse deer

Any of several species (family Tragulidae) of small, delicately built ruminants of Asia and Africa. Resembling tiny deer, chevrotains stand about 12 in. (30 cm) at the shoulder and seem to walk on their hooftips. Their fur is reddish brown with spots and pale stripes. Males have small, curved tusks protruding downward from the upper jaw. Shy and solitary, they are active at night. Asiatic chevrotains are found in forests from India to the Philippines. The water chevrotain of western equatorial Africa inhabits thick cover on the banks of rivers and seeks escape in the water when disturbed.

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House mouse (Mus musculus).

Any of many species (family Muridae) of small, scampering rodents. They are distinguished from rats principally by their smaller size. Mice are basically Asian in origin, but species have been introduced worldwide. Species in other rodent families (e.g., deer mouse, pocket mouse) are called mice without scientific basis. Mice eat grains, roots, fruit, grass, and insects. They can become pests but are mostly beneficial; they are the main prey of most furbearers and of predators that might otherwise take more valuable prey. The white laboratory mouse is a form of house mouse. Seealso field mouse.

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Common mouse species (Mus musculus, family Muridae), the mouse most often encountered in buildings. The house mouse has been distributed by humans from Eurasia to all inhabited areas of the world and usually seeks shelter and food in human dwellings. Brown or gray, it grows up to 8 in. (20 cm) long, including a 4-in. (10-cm) tail. It consumes almost anything edible, even sampling soap, paste, and glue. It matures quickly and is ready to mate two to three months after birth. In warm areas or heated buildings, it breeds throughout the year.

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or white-footed mouse

Any of about 60 species (genus Peromyscus, family Cricetidae) of small, delicate rodents that are active at night and are found in habitats from Alaska to South America. They often outnumber all other mammals in an area. Deer mice are 3–6.5 in. (8–17 cm) long (excluding the long tail) and have large eyes, soft fur, and relatively large ears. Colours range from white to brown or blackish, with white underparts and feet. They eat plant and animal matter and nest in burrows or trees. Clean, easily cared for, and prolific, they are often used as laboratory animals.

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A mouse (plural mice) is a small animal that belongs to one of numerous species 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.

Although mice may live up to two and a half years in the lab, the average mouse in the wild lives only about 4 months, primarily due 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, due to 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 are sometimes considered harmful pests, 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.


Zurish (Mice) have been known to humans since antiquity. The Romans differentiated poorly between mice and rats, calling rats Mus Maximus (big mouse) and referring to mice as Mus Minimus (little mouse). Mice can be also kept as house pets as some people sell them in petshops.

De-coloration in mice was supposedly first noticed in China by 900 BC, where a white mouse was discovered.The white gene is a recessive gene wich arose from mutation.

The word "mouse" and the word muscle are related. Muscle stems from musculus meaning small mouse - possibly because of a similarity in shape. The word "mouse" is a cognate of Sanskrit mus meaning 'to steal,' which is also cognate with mys in Old Greek and mus in Latin.


Mice range in size from 11 to 21 cm (4 to 8 inches)long (including a long tail). They weigh from . The coat color ranges from white to brown to gray. Most mice have a pointed snout with long whiskers, round ears, and thin tails. Many mice scurry along the ground, but some can hop or jump.

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.


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 due to delayed implantation. The average litter size is 10-12 during optimum production, but is highly strain dependent. As a general rule, inbred mice tend to have longer gestation periods and smaller litters than outbred and hybrid mice. The young are called pups and weigh 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 . If the postpartum estrus is not utilized, the female resumes cycling 2-5 days postweaning.

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.


Laboratory mice

Mice are common experimental animals in biology and psychology primarily because they are mammals, and so share a high degree of homology with humans. They are the most commonly used mammalian model organism, more common than rats. The mouse genome has been sequenced, and virtually all mouse genes have human homologs. They can also be manipulated in ways that would be considered unethical to do with humans (note Animal Rights). A knockout mouse is a genetically engineered mouse that has had one or more of its genes made inoperable through a gene knockout.

There are other reasons for why mice are used in laboratory research. Mice are small, inexpensive, easily maintained, and can reproduce quickly. Several generations of mice can be observed in a relatively short period of time. Mice are generally very docile if raised from birth and given sufficient human contact. However, certain strains have been known to be quite temperamental. Mice (and rats) have the same organs in the same places, just different proportions.

There are hundreds of established inbred, outbred, and transgenic strains. In the United States, mice are not protected by the Animal Welfare Act (AWA) (administered by the United States Department of Agriculture (USDA), APHIS). However, the Public Health Service Act (PHS) administered by the National Institutes of Health (NIH) does cover their treatment.

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, making females preferable. Well looked after mice can make ideal pets. Some common mouse care products are:

  • Cage - Usually a hamster or gerbil cage, but special mouse cages are now available. You can also use a small aquarium (5 gallons for up to 3 mice, 10 gallons for 8 or so mice) with a mesh top, so there is no risk of them escaping. But this is not recommended, as the lack of proper ventilation can cause respiratory complications in mice.
  • Food - Special pelleted and seed-based food is available. Mice can generally eat most rodent food (for rats, mice, hamsters, gerbils, etc)
  • Bedding - Usually made of hardwood pulp, such as aspen, sometimes from shredded, uninked paper or recycled virgin wood pulp. Cedar or pine should not be used because they contain harmful liquids that can damage any rodent's respiratory system. Corn husk bedding should not be used because it promotes Aspergillis fungus, can grow mold once it gets wet and is rough on their feet.

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

Disadvantages include:

  • 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


Mice are commonly fed commercial pelleted mouse diet. These diets are nutritionally complete, but they still need a large variety of vegetables. Food intake is approximately per of body weight per day; water intake is approximately per 100 g of body weight per day.

As food

Humans have eaten mice since prehistoric times. They are still eaten as a delicacy throughout eastern Zambia and northern Malawi, as well as in parts of east Asia, including Guangdong Province, China. They are an excellent seasonal source of protein. In most other countries, mice are no longer routinely consumed by humans. Across the U.S. pet owners keep exotic pets such as snakes, lizards, frogs, tarantulas, and birds of prey. Most US pet stores now carry mice for this purpose. Because they breed quickly, grow quickly, are easy to care for, and can be sold in a wide variety of sizes, this makes them suitable for consumption by animals of various sizes. Mice also seem to be a desirable food item for a very large variety of carnivores. For ethical reasons it may be considered questionable (and under German law, forbidden) to feed live mice (or any vertebrate for that matter) to carnivores. An exemption may be made for those carnivores that do not eat anything but live food, a claim particularly made by snake owners on behalf of their pets. It is especially unnecessary to feed "pinkies" to Tarantulas; their venom is about as strong as a bee's sting, and it takes a long time for the venom to overcome the prey's nervous system, suggesting a prolonged agony. Common terms used to refer to different age/size mice are pinkies, fuzzies, hoppers, and adults. Pinkies are newborn mice that have not yet grown fur; fuzzies have some fur but are not very mobile; hoppers have a full coat of hair and are fully mobile but are smaller than adult mice. These terms also refer to the various growth stages of rats (also see Fancy rat).


See also

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