There were a lot of bumblebees on the buddleia in my front garden this morning. According to Wikipedia, the buzzing sound of bees is not caused by the beating of their wings. "The sound is actually the result of the bee vibrating its flight muscles, and this can be achieved while the muscles are decoupled from the wings. This is especially pronounced in bumblebees, as they must warm up their bodies considerably to get airborne at low ambient temperatures." So there you have it.
