Gerbil

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.

http://en.wikipedia.org/wiki/Gerbil