The Hemiprocnidae family includes the treeswifts. There are four species in this family. Treeswifts are found in Asia, the Asian Pacific Islands, and Australia.

Treeswifts spend much of their time in flight. They are insectivores and catch their prey in the air. Treeswifts are found in forested areas and woodlands.

Treeswifts have crests on their heads and, unlike the swifts, they can perch. They have long, pointed wings and long, forked tails. Both the male and the female build the nest. The female lays one egg.