How does a grasshopper make sound?

Grasshoppers make sounds in one of two ways - stridulation or crepitation.

Stridulation involves rubbing one body part, which acts as a rasp, against another, which acts as a scraper. Most grasshoppers stridulate to make their characteristic sounds. In grasshoppers, a row of pegs along the inside of the hind leg acts as a file, or rasp. The grasshopper rubs this leg surface against the thickened forewing, causing a vibration and thus a sound.

A few grasshoppers, most notably some band-winged grasshoppers in the family Oedipodinae, use an entirely different method of sound production, called crepitation. These grasshoppers snap their hindwings rapidly as they fly, making a distinct crackling sound.