Found the Bees

Dutiful daughter figured out where they were coming from. There is a little bump-out of the side wall of the house to accommodate the gas fireplace. It has it's own little roof. It's like a secret room, but there is no way in or out, except through the vents. I initially discounted this as the source of the bees we've been finding in the house because the vent from the fireplace is warm - the pilot light is on. I figured the bees wouldn't be going somewhere where it's hot. But now I realize that it has been getting cool at night, and they might find the pilot light very attractive.