Several members have had swarms. If your colony is strong and you are not checking for swarm cells, you are making an unfortunate mistake.
I got a text from Heather Lochner just now. What she did is what everyone should do. She checked for swarm cells. Found some. Then she found the queen and moved her and several frames to a new box. It's called an artificial swarm. You just have to be sure their are no queen cells on the frames that go with the queen. Take several food frames, as the box with the queen (if it's in a new spot) won't get foragers. You can also switch the location. Put the box with the queen on its original spot and the boxes with the swarm cells anywhere. Foragers will return to support the queen and her colony. The colony with the swarm cells doesn't need much. It will be at least two weeks before the virgin queen will begin laying.
Now suppose you can't find the queen. Well, do the opposite. Shake all the bees off every frame into the bottom box. Move anything that has a queen cell on it to a new box. Put that box above a queen excluder just long enough for nurse bees to go up to take care of the brood. (An hour or two?). Then move the box with the swarm cells elsewhere. There won't be foragers going in to that box. So take some food frames. They won't need much because soon there will be no larva.
You should check for new swarm cells every week for a month or so.
Hope this makes sense. You can do it!
By the way, I was in Tom Leith's hives today. After seven years of beekeeping I still have new experiences all the time. He had a good size swarm from one of his colonies AND three small swarms. The small swarms are called "after swarms" and USUALLY happen after the virgins emerge. I've never seen it happen with the main swarm. To make it even more interesting, he had NO swarm cells on the bottom of the second brood box. Only a few swarm cells on a few frames. Usually those are supercedure cells but this was a swarm, not a supercedure. As if that wasn't enough unusual, there was one absolutely gorgeous capped queen cell and other queen cells that had eaten there way out and didn't kill the other capped queen cells. Those became the virgin queens for the "after swarms". Confused? I am! But amazed, too.
We put the main swarm and the after swarms into the same bait hive box. I'm keeping it at my house. I'll go in tomorrow and see if I can find the virgin queens. They'll get moved to their own mating nucs.