Paintings of horned bulls, milking cows, and calves appear in Egyptian tombs. We know their domestication dates back to the earliest permanent human settlements near the Tigris and Euphrates rivers in Mesopotamia, as well as the Indus River valley in modern Pakistan. Dogs were certainly the first domesticated animal, with their utility to hunting tribes obvious. Sheep and goats were next, as they could easily be moved by still-nomadic tribes. But when humans settled into agricultural communities instead of chasing herds across continents, cattle were a logical choice for domestication from the large wild aurochs that were already valued for their meat. By domesticating the wild cattle, humans gained a consistent food and milk source, as well as fertilizer for their fields and hides for shelter and clothing.