[AS.] A quickly-flying bird of the Swallow family. Its form and habits resemble those of the swallow. It has a shorter bill, but it has no complex vocal muscles. It nests in church steeples and under the tiles of roofs, and screams shrilly. The Australian and American swifts have rigid tips to the tail feathers. The American chimney-swallow is a swift which has acquired the habit of building in chimneys, fastening its nest, which is made of small twigs, to the wall by a strongly adhesive secretion. This glue is spread over the whole nest, and becomes very hard.