Commuting to work on the MUP last summer, fixed gear, riding at a fairly fast pace, shades on, passing pedestrians.....boom, bee flew right into one of the vents on the helmet and immediately stung me. I never felt the bee hit my head, just the sting. Stopped and ripped my helmet off but it was too late. The only problem? I shave my head so it had already welted up and by the time I got to work, they had me ice it and put some Hydrocortisone cream on it. That hurt like crazy and was just throbbing and pulsing. It really hurt, way more than I would think that it would.