What is bird's nest?

The Bird's Nest is a kind of bird called "Jin Siyan", which is made by mixing their feathers and saliva with fresh moss, seaweed and soft plants.

People take this bird's nest down, and after refining and selecting it, it becomes a valuable bird's nest. Jin Siyan nests three times a year, and the first nest is thick and white. Because Jin Siyan has a long winter, a long rest time, enough nutrients are stored in the body, and the quality of saliva is better, so the nest built is better and thicker, shaped like a lamp, hence the name Zhan Yan, which is the best in bird's nest.