Sad day for drones. We actually had a season this year in which there were a number of late swarms in my high mountain valley. The colonies were communicating about this, via the drones, and so were continuing to carry the drones until quite late in the season. However, after a very early autumn daytime snow, followed by a 17° night, followed by another 25° night, the forage was largely depleted. They began evicting the drones as soon as they learned that the forage had been so diminished by the freezes.