Katydid is the common name of insects belonging to the grasshopper family Tettigoniidae, which contains over 6,800 species.

Katydid are also known as “long horned grasshoppers” and “bush crickets.” The term “katydid” is used mainly in the U.S., Canada, and Australia. The name “katydid” comes from the sound produced by species of the N. American genus Pterophylla (literally “winged leaf”). The males of katydids have sound-producing (stridulating) organs located on their front wings which in some species produce sound supposedly like “Katy did, Katy didn’t”, hence the name. Females are also capable of stridulation in some species.

There are about 255 species in N. America, but the majority of species live in the tropical regions of the world.

The diet of katydids includes leaves, flowers, bark, and seeds, but many species are exclusively predaceous, feeding on other insects, snails or even small vertebrates.