1. Bird's nests are produced by swiftlets of the Swiftidae family and a variety of swallows of the same family.

2. Their saliva is mixed with down feathers to build a nest, which can become a bird's nest. Moreover, the bird's nest directly picked cannot be eaten immediately and must be processed before it can be eaten.

3. Mainly produced in Southeast Asian countries such as Malaysia, Indonesia, Thailand and Myanmar, as well as the coastal areas of Fujian and Guangdong in my country. Bird's nest is rich in sugars, organic acids, free amino acids and characteristic substances - sialic acid. The main nutrient in bird's nest is protein, which includes 1 essential amino acid (lysine) and 3 conditionally essential amino acids. The human body needs 8 essential amino acids and 13 conditionally essential amino acids.