Once on a college bee exam (hey, i was at Cornell, i HAD to take the bee course!) there was a question about swarming (What's it caused by?). I answered with the usual stuff - congestion of the brood nest,etc. I also had a great idea while answering this question, and put down that with the increased population the concentration of queen substance was less (per bee, i mean). Doc Morse graded the exam and when i got it back there was an emphatic "NO!" sprawled across that part of my answer. Never did get to ask him about it. Still seems plausible to me. If this were the case, then maybe inserts like apistan strips, but with queen substance in them would allow for larger populations and more congestion without the swarming impulse arising...? If anybody can add to this, about queen substance, i'd appreciate more info too. Thanks muchly, JWG