Striulation is the act of producing sound by rubbing together certain body parts. This behavior is mostly associated with insects, but other animals are known to do this as well, such as a number of species of snakes and spiders. A dedicated stridulation apparatus has also been discovered in males of one (as of April, 2007) bird species, the Club-winged Manakin. Common onomatopoeic words for the sounds produced by stridulation include chirp and chirrup.