Bird's nest, also known as bird's nest, swallow root and swallow dish, refers to a nest made by mixing saliva secreted by some Swifts of Swift Family of Swift Order and Jin Siyan of several species of Swiftlet in Jin Siyan with other substances. Bird's nest can be divided into "domestic swallow" and "cave swallow" according to the nesting location. Dongyan is influenced by minerals in different colors, including Bai Yan, Huangyan and Hongyan, while domestic swallow is only ivory white.