Periodical cicadas are largely restricted to areas east of the Mississippi River and do not occur in Colorado. When full-grown, nymphs emerge from the soil. They crawl up a nearby plant or wall, and the nymphal skin splits along the back. The adults pull themselves from the old skin and hang from the plant for several hours, pumping blood to extend the wings. The new exoskeleton hardens and darkens rapidly and the Insects then fly away, leaving behind their cast nymphal skins.
Male cicadas attract females by their characteristic songs.
Most cicadas have a pair of tymbals or domed, drum-like organs on the sides of the abdomen. They alternately contract and release muscles to make the tymbals resonate. A large air sac in the abdomen with a thin exterior eardrum acts as an echo chamber that greatly amplifies the sound. One group of common Colorado cicadas lack tymbals. Instead, they produce sounds by clicking together their wings, somewhat like certain grasshoppers and crickets.