Tettigoniids may be distinguished from grasshoppers by the length of their filamentous antennae, which may exceed their own body length, while grasshoppers' antennae are always relatively short and thickened. The males of tettigoniids have sound-producing organs (via stridulation) located on the hind angles of their front wings. In some species females are also capable of stridulation. The males provide a nuptial gift for the females in the form of a spermatophylax, a body attached to the males' spermatophore which is consumed by the female. The function of the spermatophylax is to increase the attachment time of the males' spermatophore and thereby increase his paternity. The eggs of tettigoniids are typically oval shaped and laid in rows on the host plant.
There are about 255 species in North America and Europe, but the majority of species live in the tropical regions of the world.
The diet of tettigoniids includes leaves, flowers, bark, and seeds, but many species are exclusively predatory, feeding on other insects, snails or even small vertebrates such as snakes and lizards. Some are also considered pests by commercial crop growers and are sprayed to limit growth. Large tettigoniids can inflict a painful bite or pinch if handled but seldom break the skin.