The genus Peromyscus contains the animal species commonly referred to as deer mice. This genus of New World mice is only distantly related to the common house mouse and laboratory mouse, Mus musculus. Although superficially resembling Mus musculus, Peromyscus species have relatively larger eyes, and also often two-tone coloring, with darker colors over the dorsum (back), and white abdominal and limb hair-coloring. In reference to the coloring, the word Peromyscus comes from Greek words meaning “booted mouse”.

They are also accomplished jumpers and runners by comparison to house mice, and their common name of “deer mouse” (coined in 1833) is in reference to this agility.

The most common species of deer mice in the continental United States are two closely related species, P. maniculatus, and P. leucopus. In the United States, Peromyscus is the most populous mammalian genus overall, and has become notorious in the western United States as a carrier of hantaviruses.

A different mammal, the “mouse-deer”, or chevrotain, is a relatively primitive ungulate of minuscule size.

The deer mouse came to the attention of the public when it was discovered to be the primary reservoir species for Sin Nombre hantavirus.

Lyme disease
A recent study in British Columbia of 218 deer mice showed 30% (66) were seropositive for B. burgdorferi,[7] the agent of Lyme disease.

Other diseases
Ehrlichiosis and babesiosis are also carried by the deer mouse.

Peromyscus is used as a laboratory animal. Peromyscus is also easy to breed and keep in captivity, although they are more energetic and difficult to handle than the relatively more tame Mus musculus. It is also favoured over the common laboratory mouse (Mus musculus) and the laboratory rat (Rattus norvegicus). They are also useful for researching repetitive movement disorders.