Years ago I was cycling along in Durango on a beautiful sunny afternoon. I saw something heading my way and next thing I know a decent sized bug is in my mouth, I pursed my lips to spit it out instinctively and the bastard latched onto my lower lip and stung the crap out of it. I managed to swat it off and come to stop without incident. By the time I got home I had one heck of a fat lip.
On my Ducati a few years ago I was cruising with the visor up on a residential section of Alhambra Valley Road, felt a bug get into the helmet but didn't think anything of it, figured I was going fast enough it was dead. A while later I'm enjoying a brisk pace when the no longer dazed bee starts wandering along the base of my visor. Got myself pulled over rather quickly, gingerly took off my helmet and managed to drop the bee off on a tree branch.
Most recently I was riding in some rather hot weather down south and thus had my jacket unzipped around the next. Felt something sting around my ribs, right below my left pectoral, gave a quick smack and figured that was that. Got two more sharp stings and proceeded to punch myself in the chest a few times, never did find the offending bugger, but I had a solid welt for a week or so afterwards.