Mouse (genus Mus), house mouseEncyclopædia Britannica, Inc.the common name generally but imprecisely applied to rodents found throughout the world with bodies less than about 12 cm (5 inches) long. In a scientific context, mouse refers to any of the 38 species in the genus Mus, which is the Latin word for mouse. The house mouse (Mus musculus), native to Central Asia, has established itself with human populations in many other parts of the world.