A 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, where they inhabit caves and buildings. Swiftlets are unique for their ability to produce edible nests made of hardened saliva, which are highly valued in some cultures. The nests of Swiftlets are often harvested for use in traditional dishes, such as bird's nest soup, particularly in countries like China and Indonesia. These nests are considered a delicacy and are believed to have health benefits. Swiftlets are also known for their echolocation abilities, allowing them to navigate in dark environments.