The word "mouse" has no scientific meaning, but species of many families of small rat-like rodents are referred to as mice. Most mouse species, such as the common house mouse, belong to the family Muridae. Over 1300 species of murid rodents have been identified, making Muridae undoubtedly the largest family of mammals currently in existence. Members reside in nearly every habitat on all continents except Antarctica and may even be found on many oceanic islands. In numerous locations, however, species were introduced by humans, rather than occurring naturally.