The production of sounds by rubbing two parts of the body together; best known in crickets, grasshoppers and cicadas. Larval Lucanidae, Passalidae and Geotrupidae also stridulate, rubbing a series of ridges on the coxa of the middle legs with the plectrum on the trochanter of the hind leg.
Stridulation is the production of sounds by an insect or other arthropod by rubbing together two parts of its body, referred to generically as the stridulatory organs, though in many groups the entire structure is called a stridulitrum. The mechanism is best known in crickets and grasshoppers, but other insects which stridulate include Scolytinae (bark beetles), Cerambycidae (longhorned beetles), Mutillidae ("velvet ants"), Reduviidae ("assassin bugs"), the Black imported fire ant (Solenopsis richteri) and larval Lucanidae (stag beetles), Passalidae (Bessbugs), and Geotrupidae (earth-boring dung beetles). Stridulation is also known in some species of millipede (class Diplopoda).