There was a strong wind last night - warnings of gusts up to 40mph. Thankfully my hives remained upright. The weather was still windy when I visited Hive D this morning at 11am, but it was just about warm enough to lift the lid.
I had been concerned that the bees were too cramped in Hive D. I also found wisps of the hessian which I've used to contain the straw in the insulated box. I imagined that the bees were brimming over and chewing through the hessian.
My fears were unwarranted. The cluster was toward the front of the hive. There was even space toward the back where they haven't built comb on the frames.
The bees were apparently unconcerned when I took the roof off. Some stayed on the excluder which I'd used to separate the brood area from the insulating box. The rest ignored me. I added a super which has 8 frames with comb and 4 without.
I'm surprised that there is a brood box frame which hasn't been built up with comb. I'd like them to fill all the volume. Perhaps the volume of a Commercial box is more than they need. I could probably encourage them to fill it by feeding, but then they'd also build up loads of stores and maybe make the brood nest cramped with stores. The super which I've just added makes it likely that they'll fill vertically.
As my bee group would suggest, I'm not going to try to manipulate the bees to build here or there. They'll work it out for themselves.