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