A male cricket has a heavy vein with a row of teeth on the underside at the front of each wing. The top of one wing was used as a scraper against the underside of the other wing, like a fingernail drawn along the teeth of a comb. This performance occurs with both wings elevated so that the wing membranes can act as sounding boards. The pitch of the chirps is slightly higher than the highest octave on a piano. Air temperature influences chirping rates; the warmer the night, the faster they chirp. There are special songs for courtship, fighting, and sounding an alarm.