Bird's nest, also known as bird's nest, bird's nest root, swallow vegetables, for the swiftlet family animal swiftlet and a variety of species of the same genus of swiftlets with saliva and down feathers and other mixed condensation of the nest, shaped like a treasure, the nest outside the wall of the dense filaments by the crossbar piled up into an irregular prismatic protrusion, the nest inside the wall of the filaments by the silk woven into an irregular mesh, the nest of the bowl of the roots but solid, the two ends of the small drop angle, generally 6 ~ 7 cm in diameter, 3 ~ 4 cm deep. It is mainly produced in China's South China Sea islands and Southeast Asian countries. Bird's nest can be categorized into three kinds due to different collection time: 1. White Bird's Nest: it was once listed as tribute in ancient times, so it is also known as Palace Bird's Nest; 2. Hairy Bird's Nest; 3. Blood Bird's Nest. Bird's nest is highly nutritious, containing 50% protein, 30% sugar and some minerals. It is one of the famous traditional Chinese foods. The maker of bird's nest, of course, is the swiftlet, but this kind of swiftlet is not the common one that builds nests under the eaves of the house. Swallows under the eaves are called house swallows (swallows), belonging to the family of swallows, and their nests are made of grass or mud mixed with saliva, making them inedible and of little nutritional value. Eatable bird's nests are made by another kind of swiftlet, which belongs to the swiftlet family and is called "swiftlet". It refers to the nests made by the saliva secreted by some of the swiftlets in the rainbird family of the order Rainbird Barns, and several species of swiftlets in the genus Swiftlet, which are mixed with other substances (e.g. feathers), instead of the nests made by birds of the family of the bird family of the order Birdnests, e.g. the House Swiftlet. The protein purity and nutritional value of swiftlet saliva is the highest. It is produced in the coastal areas of southern China, Vietnam, Thailand, Malaysia, Indonesia and the Philippines. Bird's nests are categorized into "House Swallows" and "Cave Swallows" according to the nesting place. The nests of "House Swallows" are usually built on top of the bird's nests which are carefully constructed by human hands to facilitate the collection of bird's nests, while the nests of "Cave Swallows" are built in caves, which is a dangerous place to collect bird's nests. Some bird's nests are called "blood bird's nests" because of the reddish color of the swiftlet's saliva due to the presence of seaweeds in its diet, not because of any misunderstanding that the swiftlet has not completed its nest and is spitting out blood because it is holding back from laying its eggs. After the bird's nest is harvested, it has to go through complicated processing such as steaming, soaking, removing impurities, picking hairs and drying before it can be made into finished bird's nests, including marigolds, bird's nest bars, bird's nest cakes and bird's nest threads. Bird's nests are made by removing impurities and retaining the original shape of the entire bird's nest, which is particularly expensive. Bird's nests are the nests of the seabird, swiftlet. It is mostly built on the cliffs of tropical and subtropical islands, surrounded by rolling waves, with blue sky and white clouds above. Swiftlets start to make nests in the spring, and its mouth can secrete a kind of gelatinous saliva, which becomes translucent and slightly light yellow after being spat out and blown dry by the sea breeze, which is the main ingredient of the bird's nest. The swiftlet uses this saliva to make a nest with delicate seaweeds, down feathers and soft plant fibers, which is what we call "bird's nest". Bird's nest is a precious delicacy, but also valuable medicinal herbs, the text has the effect of tonifying the lungs and nourishing the yin, the main treatment of deficiency cough, coughing up blood and other diseases. India, the Malay Archipelago and China's Hainan Island and the South China Sea Islands, etc. are produced

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