Either of two species of large, hump-backed ruminants of the family Camelidae. Camels are used as draft and saddle animals in desert regions of Africa, Arabia, and Asia. Adaptations to windblown deserts include double rows of eyelashes, the ability to close the nostrils, and wide-spreading soft feet. They also can tolerate dehydration and high body temperatures. They are thus able to go several days without drinking water. Though docile when properly trained, camels can be dangerous. The Bactrian camel (Camelus bactrianus) is about 7 ft (2 m) tall at the top of the two humps; the Arabian camel (C. dromedarius), or dromedary, has one hump and is 7 ft (2 m) high at the shoulder. When food is available, camels store fat in their humps to be used later for sustenance; water is produced as a by-product of fat metabolism. The feral camels of Australia were introduced to that continent in the 1800s.