I had something trapped in my helmet once as I flipped my face shield down while accelerating away from a traffic light. Bee, wasp, I'm not even sure. But it was a scary couple of seconds until I opened the face shield and released it.
I also had something of the stinging variety caught in my helmet when I was on a nice twisty road in West Virginia. I was at the back of the pack, so nobody saw me stop at the side of the road and waving wildly and basically freaking out. I did get stung and I did have a reaction. It was not a pleasant week with one of my eyes just about swollen shut. :shiver: