Sky burial is to feed vultures with the body of the dead. After vultures finish eating the body and fly into the sky, Tibetans think that the dead will go to the heaven. It is the usual means adopted to dispose of the corpses of commoners, and is not considered suitable for children who are less than 18 years old, pregnant women, or those who have died of infectious disease or accident. Even today, the origin of sky burial remains largely hidden in Tibetan mystery.