One of my hives has suffered an unfortunate demise because of a mistake I made two months ago. At the time, I did an inspection of the hive and found: - a high population of adult bees (as high or higher than last inspection) - great pattern of closed brood - no open brood or eggs - 3 frames with queen cells (some capped, some about to be) at/near the bottom bar. I decided there are three possible explanations for this: a) The queen has suffered an unfortunate demise somehow between the last inspection and this one. b) The hive has swarmed, the old queen has left, and the new queen hasn't been born yet. c) The hive is about to swarm and the queen has stopped laying in preparation for her journey (I read it in a book that one of the preparations to swarm is "scaling back brood production"). I eliminated option (b) because the adult population was not reduced by one half as I would expect to see. I also eliminated option (a) because on my previous inspection, one week before, there were eggs and open brood, and I was reasonably sure I didn't see the queen, let alone squish her somehow. So, I decided on option (c) and to prevent the swarm, removed all the frames with queen cells to a fresh nuc. Turns out I was wrong - the hive wasn't preparing to swarm - something had happened to the queen. On next inspection, it was plain that the hive was queenless - no brood of any kind and no sign of a queen. Thus, I made a judgement error due to lack of experience and crippled the hive when I should've left it alone to raise a queen, or requeened it. My question is: what could I have done better? What should I have looked for to better distinguish between choices (a) and (c) above? Thank you.