Excavation of Cordyceps is one of the most important sources of economic income for Tibetan friends. It is necessary to rely on the local acquisition certificate to enter the mountain to dig the Cordyceps, and those who do not have a certificate of collection cannot enter, and the government is particularly strict. Children have become the main force in the excavation of Cordyceps because of their good eyesight, fast legs and light body. When chatting with local Tibetan friends, they know that the school here will put "Chongcao fake" every year, and the last semester is generally only short. It is less than three months short, and the next semester will last from July to the end of the Cordyceps period until the end of the year.