Mice



A mouse (plural mice) is a rodent that belongs to one of numerous species of small mammals. The best known mouse species is the common house mouse (Mus musculus). It is found in nearly all countries and, as the laboratory mouse, serves as an important model organism in biology; it is also a popular pet. The American white-footed mouse (Peromyscus leucopus) and the deer mouse (Peromyscus maniculatus) also sometimes live in houses. These species of mice live commensally with humans.

Although they may live up to two years in the lab, the average mouse in the wild lives only about 3 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 incredible adaptability to almost any environment, and its ability to live commensally with humans, the mouse is regarded to be the third most successful mammalian species living on Earth today, after humans and the rat.

Mice can be harmful pests, damaging and eating crops and spreading diseases through their parasites and feces. In the Western United States, 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.

Body and behavior
Mice are small rodents, resembling diminutive rats. Usually they have pointed snouts and small ears. The body is typically elongated with slender, usually hairless tails, but different types of mice show large variations. Body dimensions vary considerably by species, though some approximate values are available: total length 28-130 mm, mass 2.5 to >34g

Mice generally live on an herbivore diet, but are actually omnivores; they will eat meat, the dead bodies of other mice, and have been observed to self-cannibalise their tails during starvation. Grasshopper mice are an exception to the rule, being the only fully carnivorous mice. Mice eat grains, fruits, and seeds for a regular diet, which is the main reason they damage crops. They are also known to eat their own feces. Mice are generally thought to enjoy cheese and people sometimes use it as mousetrap bait, but mice actually do not like cheese due to its fatty texture. Instead, they like food that contains high sugar, like chocolate.

Mice are social animals. They prefer to live in groups. Male rivalry can become harmful for the animals, especially when a group is confined to a small space. The natural habitats of the mouse are very diverse. Mice can be found in forests, savannahs, grasslands and rocky habitats. In Africa they tend to particularly like forest edge, derived savannah, and (as elsewhere) agricultural areas. Mice build nests for protection and warmth, but species differ in their preferences: M. minutoides nests in shallow burrows; M. caroli and M. cervicolor burrow; and M. shortridgei and M. pahari nest aboveground. Most species will construct nests of grass, fibers, and shredded material. Mice do hibernate.

The mouse has dichromatic vision, lacking a photopigment that can detect red light. Diseases spread by mice and rats

It is important to get rid of mice quickly because they can spread serious disease to people.

Some of the diseases they carry or cause include:


 * Rickettsial pox a disease similar to chicken pox and is spread to people by mites that are usually found on mice.


 * Rat bite fever is spread to people when they are bitten by an infected mouse, rat or rodent.


 * Food poisoning (namely salmonellosis) is spread to people when food, food preparation surfaces or dishes are contaminated by saliva, urine or feces from a mouse.


 * Mice can spread parasites to people such as trichinosis and tapeworms.


 * Hantavirus is a respiratory disease that is carried by small rodents, especially deer mice. It is spread to people when they breathe in dust that contains the rodents infected saliva, urine or feces. Although uncommon, people can also get hantavirus if they are bitten by an infected mouse.


 * Plague is spread to people when they come in contact with fleas from infected rodents or when people are bitten by infected rodents. However, today plague is usually spread to people by rodents like prairie dogs and squirrels.

Effects of caloric restriction
Studies in female mice have shown that estrogen receptor-alpha declines in the pre-optic hypothalamus as they grow old. The female mice that were given a calorically restricted diet during the majority of their lives, maintained higher levels of ERα in the pre-optic hypothalamus than their non-calorically restricted counterparts. Studies in female mice have shown that both Supraoptic nucleus (SON) and Paraventricular nucleus (PVN) lose about one-third of IGF-1R immunoreactive cells with normal aging. Also, Old caloricly restricted (CR) mice lost higher numbers of IGF-1R non-immunoreactive cells while maintaining similar counts of IGF-1R immunoreactive cells in comparison to Old-Al mice. Consequently, Old-CR mice show a higher percentage of IGF-1R immunoreactive cells reflecting increased hypothalamic sensitivity to IGF-1 in comparison to normally aging mice.

Taxonomy of the genus Mus
The term "mouse" in common usage is roughly equivalent to the taxonomic term Mus, while house mouse is equivalent to Mus musculus. In common language the term "mouse" often refers incorrectly to Mus musculus. However, there are 38 species of mice (in the genus Mus); see table below.

Laboratory mice
Mice are the most commonly utilized animal research model with hundreds of established inbred, outbred, and transgenic strains. In the United States, they are not covered under the Animal Welfare Act (AWA) (administered by the USDA, APHIS) as an animal. However, the Public Health Service Act (PHS) as administered by the National Institutes of Health (NIH) does cover their humane treatment.

Mice are common experimental animals in biology and psychology primarily because they are mammals, and thus share a high degree of homology with humans. 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. Mice are a primary mammalian model organism, as are rats. There are many additional benefits of mice 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.

History
Mouse-like species are among the oldest mammals. It has been proposed that higher mammals evolved from rodent-like species many million years ago.

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). In Spanish similar term are in use: ratón for mouse and rata for rat.

Discoloration in mice was supposedly first noticed in China by 1100 BC, where a white mouse was discovered. However, there is sufficient evidence to believe that white mice were first noticed before that, in the times of the Greeks and Ancient Rome.

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 mush meaning 'to steal,' which is also cognate with mys in Old Greek and mus in Latin.

Mice as food
Humans have eaten mice since prehistoric times. They are still eaten as a delicacy throughout eastern Zambia and northern Malawi, where they are an important source of protein.

A common use of mice is to feed many species of snakes, lizards, 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, they can be sold in a wide variety of sizes. This makes them suitable for consumption by animals of many different sizes. Mice also seem to be a desirable food item for a very large variety of carnivores. 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 generally 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).

Mice specifically bred for pets and feeders are sometimes called fancy mice.

Mice as pets

 * Main article: Fancy mouse

Mice have turned into a popular pet. Although their main purpose in pet stores is to be sold as snake food, many people buy mice as companion 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.
 * Food- Special pelleted and seed-based food is available. Mice can generally eat most rodent food (for rats, mice, hamsters, gerbils, etc)
 * Bedding- Usually hardwoods, such as aspen, though shredded, uninked paper or recycled virgin wood pulp can also be used. Cedar or pine should not be used because they contain harmful liquids that can damage any rodent's respiratory system. Corn cob bedding should also not be used because it promotes Aspergillis fungus and can grow mold once it gets wet. It also is quite rough on their feet. Whatever the bedding material, there should be at least 2 inches for digging and burrowing purposes.

Some benefits of having mice as pets are
 * Minimal shedding and allergens
 * Entertaining and affectionate
 * Inexpensive
 * Clean (contrary to popular belief)
 * Socially self-sufficient (when in a group of other mice)
 * Significantly less likely to bite than other rodent pets
 * Mice are quite intelligent given their size

There are, however, some disadvantages to having pet mice
 * Small and quite fragile (not as easy to handle as a dog or a cat)
 * Mice defecate and urinate frequently, especially while being handled by children.
 * Nocturnal
 * Frequent eye infections under stress
 * Easily subject to disease when without optimal care
 * Frequent reproduction
 * Short lifespan
 * Prone to many other diseases