True katydids are relatives of grasshoppers and crickets. They grow over two inches long and are leaf-green in color. Katydids have oval-shaped wings with lots of veins. They resemble leaves. True katydids live in forests, thickets, or fields with lots of shrubs or trees. Katydids spend most of their time at the tops of trees where most of the leaves are. Usually katydids are heard, but not seen. Unlike grasshoppers and crickets, both male and female katydids make sounds. They rub their forewings together to "sing" to each other. Katydids hear each other with ears on their front legs.

Breeding season is in late summer and early fall. Females will lay eggs on stems. Eggs will hatch the following spring into nymphs, young katydids not fully grown. Katydid nymphs eat and grow, molting their skin several times. Each time the nymph sheds its skin it looks more like an adult. Finally, after its last molt, the nymph has changed into an adult katydid.

True Katydids eat leaves of most deciduous (lose leaves in Fall) trees and shrubs, especially oaks. Katydids can fly short distances when threatened, but they prefer to walk and climb. When they do fly, it is more of a downward flutter. If a katydid lands on the ground, it will walk to the nearest tree and climb. Predators of True Katydids include birds, bats, spiders, frogs, snakes, and other insect-eaters.