These are non-periodical, which means some of the adults are out each year. However, their life cycles are multi-year. We can hear them and many students have found some of their exoskeletons. Cicadas are flying insects. Some people call them locusts but they are not locusts.
Locusts are a kind of grasshopper.
The cicadas are related to leafhoppers. They feed on plants, sucking juices from tree roots. They have six legs. The front two legs look like claws when they are in the nymph stage. The adult cicadas are about 1-2 inches long.