230 beats per second

Honey bees beat their wings over a short arc of about 90 degrees at a rapid 230 beats per second and it is this high speed that makes their distinctive buzz. The sound is actually the result of the bee vibrating its flight muscles at that frequency, and the bee can achieve this while the muscles are decoupled from the wings so they also hum even without flying or moving their wings, this is a feature only known in bees but not other insects.