The Corulegastridae are a family of Odonata (dragonflies) from the suborder Anisoptera. Some vernacular names for the species of this family are spiketails and biddies. They have a large brown or black body with yellow markings. They can be found along small, clear, woodland streams, flying slowly 30 to 70 cm above the water. When disturbed, however, they can fly very rapidly. It is a small group: for instance, all species in the United States belong to the genus Cordulegaster. The Cordulegastridae usually lay their eggs in the sand in shallow water, the female hovering just above the water with her body in a vertical position, and making repeated dips into the water with her abdomen.