Mark lifted 3 boxes at once (WOW) and I put the 4th box underneath. I do not see comb in the 3rd box, so how could they really be preparing to swarm? Unless the "false floor effect" does exist - which is where the top bars of the lowest box is a "fake out" and they think it's a floor and that they are running out of room.
Needless to say, they have plenty of room now - though I've read that you can't prevent swarming (some think it's healthy hive reproduction) unless you destroy the swarm cells - guess who is NOT going to try that...unless the next post is from the ED with IV epinephrine running - for my anaphylaxis.
So here's a video and I think there are too many drones going in and out - but I usually am not down there mid-day (despite Cassie's belief that I never work, turns out, I do) so maybe this is normal activity. I sent the video to Nature's Nectar (Stillwater very experienced beekeepers) but when I looked at it on a computer screen (versus my iPhone) it's kind of fuzzy so they may not be able to tell me anything.
and here's an even worse video (it is a martin flying off of my martin house - who, by the way, came back the next day - Monday - and we haven't seen him since). One of these days, the martins WILL set up camp here (the birds singing in the background is my martin CD "dawn song" trying to attract a colony):