There is a larger than fist-sized cluster congregated under the screened bottom board. The mite board insert has been removed. What could be going on there? I didn't see anything awry on the bottom board last week when I did a hive inspection.
This is one reason why I quit using them as well. Had queens mating on days with cold nights. Found queens and clumps of bees dead from cold on the pallet under my hives. Some were still hanging on.One of the reasons I gave up on SBB's was the fact that over the years I have had many hives supercede and the new queen returns from her mating flights and ends up under the screen, Over time the hive dwindles and becomes broodless and when you get to the bottom you find where they have attempted to build comb and raise brood, by then it is too late and the hive is done, So they will not build comb under thr screen unless there was a young queen there.