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 also
sometimes live in houses. In some places, certain kinds of field mice are also common. This rodent is eaten by large birds
such as hawks and eagles. They are known to invade homes for food and occasionally shelter.
Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. "True rats" are members of the genus Rattus,
the most important of which to humans are the black rat, Rattus rattus, and the brown rat, Rattus norvegicus. Many members
of other rodent genera and families are also called rats and share many characteristics with true rats. Rats are typically
distinguished from mice by their size; rats are generally large muroid rodents, while mice are generally small muroid rodents.
The Old World rats and mice, part of the subfamily Murinae in the family Muridae, comprise at least 519 species. This subfamily
is larger than all mammal families except the Cricetidae, and is larger than all mammal orders except the bats and the remainder
of the rodents.
The House Mouse (Mus musculus) is one of the most numerous species of the genus Mus commonly termed a mouse. It is a small
mammal and a rodent. Laboratory mice belong to strains of House Mice and are some of the most important model organisms in
biology and medicine; they are by far the most commonly used genetically altered laboratory mammal.
A Gerbil is a small mammal of the order Rodentia. Once known simply as "desert rats", the gerbil subfamily includes about
110 species of African, Indian, and Asian rodents, including sand rats and jirds, all of which are adapted to arid habitats.
Most are primarily diurnal (though some, including the common household pet, do exhibit crepuscular behavior), and almost
all are omnivorous.
The brown rat, common rat, sewer rat, Hanover rat, Norway rat, Norwegian rat, or wharf rat (Rattus norvegicus) is one of the
best known and most common rats. One of the largest muroids, it is a brown or grey rodent with a body up to 25 cm (10 in)
long, and a similar tail length; the male weighs on average 350 g (12 oz) and the female 250 g (9 oz).
