A swarm of bees is a marvelous opportunist. I’d left a couple of flower pots in my back garden. They’d previously contained bee hives which had been removed. I was intending to clean them out and use them again, as flower pots. The swarm of bees got there first!
I should have known better than leave a flower pot with traces of beeswax upside-down at the start of swarming season. It was an open invitation to any passing swarm of bees.