Zoologically, there is no distinction between mice and rats; these names being employed respectively for most or all of the smaller and larger "mouselike" and "rat-like" representatives of the Muridae, whether they belong to the genus Mus or not.
Of the Muridae there are several genera and a large number of species, some of them evidently importations from the Old World.
HAMSTER, a European mammal of the order Rodentia, scientifically known as Cricetus frumentarius (or C. cicetus), and belonging to the mouse tribe, Muridae, in which it typifies the sub-family Cricetinae.
On account of certain structural peculiarities, the rats of Madagascar, which have a dentition like that of the cricetine Muridae, are separated as a distinct family, Nesomyidae.
The characteristics of the Muridae are those of the Myoidea generally, as given above under the heading of the Spalacidae.
How would you define muridae? Add your definition here.