Thank goodness I live in Scotland, where the local fauna doesn't include much that's dangerous to humans.

i changed my helmet recently from a Giro with a mesh cover to an new Giro with bigger vents and no mesh.

I've had several buzzy things fly in (including a wasp on a couple of occassions--- not the same wasp), but have only had to whip the helmet off once. I put this down to the fact that my head is becoming more streamlined (less hairy) with each passing year.