I had a simlar incident about a month ago. I was riding along when a bee or wasp flew right into one of the air vents of my helmet. At first I wasn't sure if he just fell out, so I gave my helmet a shake to get him out if not, and rode on. About 30 seconds later I felt a sting on my head, just below the hairline. Somehow I quickly sat up, removed my helmet, and cleared the bug all while pedaling along at 20 mph . Other than hurting like hell, there was no other damage done, and I was on a lightly traveled road with no cars around.