The 'Bushmen' are the oldest inhabitants of southern Africa, where they are commonly known also as San, Khwe or as the Basarwa. These terms have all been used to refer to hunter-gatherer peoples of southern Africa. Bushmen speak a variety of languages, all of which incorporate 'click' sounds represented in writing by symbols such as "!" or "/". Genetic evidence suggests they are one of the oldest peoples in the world, resident in / around the Kalahari Desert for at least 20,000 years. The desert spans areas of nowadays' South Africa, Botswana, Namibia and Angola. The people used to live as hunter-gatherers, hunting with bows and arrows, trapping small animals and eating edible roots and berries, lived in rock shelters, in the open or in crude shelters of twigs and grass or animal skins. They made no pottery, rather using ostrich eggshells or animal parts for storing and holding liquids, that is why the animals and nature are central features in the Bushmen religious tradition, folklore, art and rituals.