Bees are so olfactory inclined that it is entirely possible that a queen that runs out of space to lay produces a diffferent chemical signature than one who is laying like crazy just to put eggs in all the 'available' cells. Bees, and most animals, live and die in a world that would be hard for us to comprehend. We are very visual and bees are very olfactory. My Bees have taught me a lot over the years. For example, smells (for me prior to bees) were good or bad but now I've learned to associate certain actions (by the bees) with certain smells that don't smell especially good or bad. For beekeepers, one of the first we 'learn' is the attack pheromone but that's because we get direct feedback
Bees communicate in ways that we may understand better as time goes on but we'll never understand all the intricate details any more than the bees understand what we're trying to communicate when we speak. For Perry's bees, they must have sensed it was time to 'bug out' from some signal, likely chemical, and given the importance of the pheromones coming from the queen(s), it was likely too much of this or too little of that
Future research that ties bee behavior to specific chemical signals (and hopefully one's that beekeepers can detect with their noses would get my endorsement! For Perry's bees, I think River nailed it when she said the queens ran out of space--it's how she signaled that problem and how the bees interpreted the signal that's a mystery--we know what happened, especially Perry
Keep thinking, there are more ideas out there
