This is the first year, other than my first, that I didn't have any of my hives swarm, nor did I catch any swarms. We're closing down swarm season at this point, if I catch anything now I'll be concerned it's an abscond instead. I'm surprised as far north as you are that you are still having swarming this late. Are you sure the hive that had bees congregating all over it wasn't just bearding?