Late on the second evening of the recent cold snap I checked the outside temperature. It was 15° F, and I was very glad I had taken the nucs into the garden shed where it was about 44°. My husband asked me if the nucs had enough ventilation, and I said, yes, each nuc had a screened bottom.
At that point he became concerned about too much ventilation, to which I replied that all the other hives—meaning all those still out in the real cold—had screened bottoms with no Varroa drawers beneath. He went ballistic.
Now, I know I had explained all this to him before but, like most men, he doesn’t listen unless I’m talking about the next meal. So I explained it all again.
I’ve talked to many beekeepers who are taking the Varroa drawers out in order to increase wintertime ventilation. Since heat rises, it doesn’t drop out the bottom—and the real heat in a hive is in the center of the cluster. Many beekeepers believe the air temperature in the space surrounding the cluster is very close to the ambient outside temperature. In other words, the hive itself is providing very little insulation. It is, after all, just a plain wooden box.
My husband argued that this was close to true—but not entirely true. He said that the few degrees of difference would have a large impact on how hard the bees had to work to keep warm—and how much fuel they had to consume to do it. He said I should replace the drawers immediately. Grudgingly, I agreed. (Okay, he is an engineer and a specialist in energy conservation, but that didn’t make the whole thing any less irritating.)
It just so happened that this conversation was taking place at 11:30 p.m. Nevertheless, we collected flashlights, boots, coats, gloves, and a stack of Varroa drawers and went trekking up that blasted hill in the middle of the night. It was snowing, blowing, and freezing. Large branches and small trees had fallen across the path, and I was muttering about them—and about men—the entire time.
We slid the drawers in place at each hive. I noticed that the lower entrances were all covered with snow such that you couldn’t even see where they were, but I decided that I would wait and clear them in the morning. For the moment, I just wanted to be done.
Now, here’s the rub. When I climbed the hill the next morning the temperature was still in the teens and the snow was even deeper. But much to my amazement, during the night the snow had melted around each of the entrance holes. So not only had the temperature gone up inside the hives, but it had climbed above the freezing point—otherwise the snow would not have melted at the opening.
In the end, the bees benefited from this little exercise, my husband is feeling smug, and I am still annoyed. Still, though, I have a new problem to solve. Perhaps I will drill holes in the Varroa drawers so they let in some air—just not all the air. I modified my top-bar hive that way last year and it works great. I’ll let you know what I decide.