The swiftlet is a small bird belonging to the family Apodidae, known for its remarkable flying abilities. These birds are primarily found in tropical and subtropical regions of Asia, particularly in countries like Indonesia, Malaysia, and Thailand. Swiftlets are unique for their ability to produce echolocation calls, which help them navigate in dark caves where they often roost. Swiftlets are famous for their nests, made from hardened saliva, which are harvested for use in bird's nest soup, a delicacy in Chinese cuisine. There are several species of swiftlets, with the most well-known being the Edible-nest Swiftlet. Their nests are highly valued, leading to sustainable harvesting practices to protect their populations.