Why did they do that?

[Terry G]

Probably right ... POST #002 .... whether it's too warm or too cold, space in the hive should always reflect the size of the colony.

Insulation can be the answer ... well insulated hives reduce the need for bees to counter wildly varying temperatures ...whilst it has been hot during the day temperatures have dropped overnight particularly when it has rained ... I note from my hive temperature monitoring, at present, they are maintaining a pretty steady 26 degrees day and night ... but they are in a heavily insulated hive.

'Chapeau', Phil, as the French say. Consider mine suitably doffed

 

[pargyle]

'Chapeau', Phil, as the French say. Consider mine suitably doffed

Trouble is that it's still only a guess ... bees do what bees do and even when you see them do it you are still left thinking .... WTF ?