I was riding down a footpath whilst delivering mail and my mirror clipped a branch as I went past. Out the corner of my eye I saw what I thought were leaves fall off and didn't think much of it, however upon looking down I noticed that it was infact a few bees and I had unfortunately knocked an entire swarm off the branch and into my lap.
They covered me, the front mail bag and the bike as well. Surprisingly enough I did not panic but brought the bike to a stop, got off the bike and jumped up and down to shake the bees off (thank you Ripley's beard of bees contestants for the tip). Once the majority were off I grabbed a letter and flicked the remaining ones off me and the bike.
They were surprisingly calm throughout the ordeal and just flew away once I knocked them off and I wasn't stung once. However a few minutes later one or two stingers worked their way through my pants and got me.
The best part was whilst I was standing there shaking the hundreds of bees off myself a bonehead that obviously lived near-by decided it was as good a time as any to mention that there was a swarm of bees and that I should be careful. He almost ended up with a fist full of bees up his clacker.
I once ended up with a yellow jacket inside my helmet. I was zipping up the highway with my visor open and the thing hit me just beside my eye and skidded along into the helmet next to my ear. A decidedly unpleasant experience. I headed for the shoulder and had my bucket off almost before I stopped. I didn't get stung though; used to have hair in those days so that probably kept it from getting through to my scalp.
