Let me check... yep, he flew away right after you spotted him. He's less interested in you than you are in him. He'd rather be on his way, so steal yourself to go open the window in the room you last saw him, turn off any artificial light in the room and he will find his way out if he hasn't already.
So roughly 2 hours ago a wasp got into the house and to say I'm scared of wasps would be a massive understatement. I haven't heard or seen it since that time as I went to the living room shut the door and watched TV. Will have died, will it be sleeping, will it be by the windows? I have no idea, I don't want to go anywhere near so if anyone can clear up where it will have gone.
