Thank you for your gracious comments. There are a number of reasons that I like to add brood boxes below the existing box:
- Bees like to keep the brood at 32 to 35 Celsius. Heat tends to rise. If you add a box on top the existing one, bees have to work harder to keep the brood warm, as now they have a big empty space above their brood for all the warmth to waft into.
- When bees build in a natural cavity, like a hollow tree, they choose to build downwards, not up. Adding a box below could be considered more “natural” for them.
- When I add box underneath, there seems to be much less tendency for them to build crazy bridge comb - instead, they follow the pattern from above. This doesn’t seem to be the case when I add a box on top. This works particularly well for foundationless frames.
- With my bees, they seem to move down and draw the new frames more quickly when I add the box below. Adding a box on top, they seem to take longer to discover it and decide to use it.
- If you add a brood box on top, you disrupt the layout of the hive. The bees will have to move their stores around and change the brood pattern to restore the shapes that they naturally prefer for their honey, pollen and brood layout.
Of course the disadvantage of adding below is that you have to lift the existing brood box off to put the new one underneath. That can be very heavy, so I usually have a third empty box and I put half of the frames in that first, then lift the old brood box.
My bees are doing well in our mild California climate, thank you! In fact, in the last 4 or 5 days, it looks like they have found a nectar flow, as the hive weight is showing a nice daily increase.
