New World rats and mice are a very diverse family of rodents that includes voles, hamsters and lemmings. Widely distributed throughout the Americas, Europe and Asia, they live almost anywhere - from high up in the mountains to dry desert. Some species never leave the tree tops, while others are mostly aquatic. This is one of the largest families of mammals, containing nearly 700 species. Sadly, around one fifth of these species are currently considered threatened or endangered.
Scientific name: Cricetidae
The shading illustrates the diversity of this group - the darker the colour the greater the number of species. Data provided by WWF's Wildfinder.