Although there are many types of mouse and rat, the words most often are used to refer to the house mouse, Mus musculus, and the Norway rat, Rattus norvegicus. These two species belong to a family of rodents known as the Muridae, the Old World mice and rats, and there are over 450 species within this group. Both species underwent their early evolution in the wilds of Asia. As humans appeared and began to settle in farms and villages, mice and rats became associated with them. As humans migrated to other parts of the world and as commercial exchanges took place around the world, mice and rats went along for the ride and became established in the OldWorld and the New World, and today may be found almost any place on earth where humans are found. At birth, mice and rats are unimposing animals, as the pups are born in an altricial state and are naked, sightless, and helpless. They develop rapidly, however, and by three weeks of age are weaned from their mother. By 1.5 to 2 months of age for the mouse, and 2 to 3 months of age for the rat, they are sexually mature. Their powers of reproduction are phenomenal and many litters, some containing more than a dozen young, can be produced in a single year. Asingle female mouse mayproduce over one hundred young in one year. As adults, mice and rats still are not imposing. They have a long, scaly, scantily haired tail, and are a grayish brown color, which is somewhat paler in the belly. Although they have poor sight, their senses of smell, hearing, and taste are all excellent.
Thanks for description - Animal life club