I had a look at two of my hives today. In the one I could find no brood except for capped, in the other there was some open brood, but also some dead open brood still in the cells. The brood nests in both of these hives were quite large two weeks ago. Kind of a sinking feeling seeing dead grubs in the cells. I figure we had our first frost two days ago (about -2 overnight) so the bees figured it was time to give brood rearing a break and cleaned out all the eggs and grubs. Am I correct in this assumption, or is there something else going on? Both hives have plenty of bees and should have had no problem covering and warming the brood.