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.