Five of us in the local bee club started TBHs this year, two of us also have existing Langs.
Three of the five hives have swarmed, mine is loaded with bees and has not swarmed to this date. I mean this baby is brimming with bees and they've drawn out all the top bars with comb.
How does one go about preventing swarming in TBHs? Or is this just a casuality and/or limitation of the TBH that one has to live with?