I was sitting the last paper of my Maths GCSE (hated the subject enough as it was) and a wasp landed in my hair and stung me on the finger as I brushed it out, having no idea what it was.
I panicked, put my hand up and waved the invigilator over, who escorted me out of the last 15 mins of the exam, in case I had an allergic reaction and went into anaphylactic shock (which would have just been the icing on the cake really!)
I've been told that another invigilator took her shoe off and smashed it into the desk, which was pretty grim for the people sitting near - so really, couldn't have been a more dramatic ending for the poor (?) wasp.