It is filled with the feces of silkworms, once damp, it will lead to the growth of germs, bring harm to the body, and even cause diseases. Silkworm sand pillow is a kind of herbal medicine to get rid of rheumatism, and its herbal name is silkworm sand. Its aliases are original silkworm shit, silkworm sand, late silkworm sand, Ma Ming liver, late silkworm vector, two silkworm sand. Its name is attested as Original Silkworm Sand (Compendium), Original Silkworm Droppings (Beilu), Silkworm Sand (Tao Hongjing), Late Silkworm Sand (Doumenfang), Horse-Ming Liver (Dongmedicine Baojian), Late Silkworm Vagina (Materia Medica Prepara), and Er Silkworm Sand (Jiangsu Herbal Medicine Zhi). Its subject source is the insect of the silkworm moth family. Its medicinal part is the dried feces of the larvae of the domestic silkworm moth.