Camels are even-toed ungulates within the genus Camelus, bearing distinctive fatty humps on their backs. There are two species: the dromedary or Arabian camel has a single hump, and the Bactrian camel has two humps. They are native to the dry desert areas of western Asia, and central and east Asia, respectively. Both species are domesticated to provide milk and meat, and as beasts of burden. Camels do not store water in their humps as is commonly believed. The humps are actually a reservoir of fatty tissue. Concentrating body fat in their humps minimizes heat-trapping insulation throughout the rest of their body, which may be an adaptation to living in hot climates.