燕窝为雨燕科金丝燕属Collocalia多种金丝燕所吐唾液或唾液与绒羽混合凝于海岸峭壁而成的窝巢，是一种名贵的滋补中药，形如半月，中凹如盏，大小如汤匙，全体由网丝状分泌物层迭造成。附壁的巢基较平齐，网丝密纹呈波状。窝内部丝较粗糙，呈丝瓜络样，外部则较细密，质硬而脆 The bird’s nest is a brood nest made from a mixture of swift saliva or saliva mixed with velvet plumes on the cliffs of the swiftlets of the swiftlet family Collocalia. It is a rare nourishing Chinese medicine, shaped like a half moon, concave in shape, The size of the spoon, the entire network caused by the proliferation of silky secretions. The wall of the attached wall is relatively flat, and the dense mesh is wavy. The inner silk of the nest is rough, showing a loofah-like appearance, and the outer part is finer, hard and brittle.