The Kalahari Desert is a harsh desert, but biologically a very active one. South Africa, Angola, Namibia and Botswana border the desert. The native tribe, known as San or Bushman by the white South Africans, is one of the oldest living tribes in the world, may be as old as 100,000 years. Even then, they do not live a settled life with agriculture or animals rearing. They are pure hunter-gatherers. They were hunted down by the white settlers of South Africa as a nuisance, and as late as the early part of 20th century, there were hunting parties organized to exterminate them.

When the San go on long hunting trips following the game, they eat a cactus-like plant and they do not feel hunger or thirst for a long period. They called it Xhoba. South Africa