Camels were domesticated more than 3,000 years ago, and to this day, humans depend on them for transport across arid environments. They can easily carry an extra 200 pounds while walking 20 miles a day in the harsh desert. Camels can travel as fast as horses but can also endure legendary periods of time without food or water—they store fat in their hump(s) to help them survive. The dromedary camel, also known as the Arabian camel, exists today only as a domesticated animal. It has one hump. The Bactrian camel is the only wild species, and it has two humps. For the names, think of the capital letter D lying on its side with just one hump: D stands for dromedary. Now think of the capital letter B on its side with two humps: B for Bactrian!