We are now seeing warmer, spring like weather, throughout the upper south and moving into the mid-west. Those further north are going to have to wait for a while longer. I’m hearing beekeepers say they are reversing hive bodies and conducting other hive manipulations involving the moving of brood frames. A word of warning, there is still cold weather, especially at night, ahead and manipulations that involve movement of brood frames in and out of the brood nest must be done with caution.
The brood nest is the area where the queen is laying eggs, the bees are raising brood, and the colony is clustering in order to keep warm during cold days and colder nights. During frigid spells, the cluster must contract in order to maintain the temperature required to prevent damage to brood. Moving brood comb around or inserting frames with new foundation (or even empty comb) into the middle of the brood area may force bees to spread out over too large an area in an effort to keep the brood warm. Brood not well covered with bees is in danger of being damaged or destroyed – chilled brood. Once nighttime temperatures are consistently in the 60s (°F), the risk is minimized. When inserting new frames, it is better to put them on the ends of the brood area rather than in the middle. The bees will draw them out and expand the brood area into the new frames.
When reversing brood boxes the same caution holds. In parts of the country which experience true winter, the normal progression is for the colony to store more and more honey and less brood in the top box as autumn wears on. The cluster then starts out the winter in the bottom box – often continuing to rear some brood there. (Here in Kentucky, it’s not unusual to have the top boxes full of honey by late summer or early fall.) This mirrors the behavior of feral bees, which move up within a hollow tree or other cavity to store surplus honey above the brood nest. As winter proceeds, honey in the bottom box is consumed, and the cluster moves into the honey stores above – which is where we find the colony in the spring. That’s when many, though not all, beekeepers follow the practice of reversing or rotating the brood boxes. Placing what had been the top box, containing bees and brood, on the bottom board and placing the empty box on top of it encourages the bees to spread into the upper box as brood rearing picks up in the spring. As I say, many beekeepers practice rotation, and some bee books instruct beginners to do it, but other beekeepers consider it unnecessary and do not. There is nothing wrong with it, but more often than not, I myself don’t bother. I find that the bees will move down into the bottom box as they need more space. If the bees have entirely moved into the top brood box it is fine to make the reversal. If they are both boxes, even though mostly in the top box, you should be careful about making this manipulation or not make it. Sometimes we will find the brood area as being in the top of frames in the bottom box and extending into the bottom of the frames in the top box. Picture the cluster as a ball centered between the boxes and in both boxes. If the bees are in this arrangement and you reverse the boxes, you will split a large cluster into two small ones. The bottom box (formerly the top box) will have a cluster in the bottom of the frames and the top box will have a cluster in the top of the frames. Two smaller clusters, which will not control the temperature as effectively as the former larger cluster or the bes may abandon brood in one of these areas. It is thus very important to not make manipulations involving reversing hive bodies or brood frames, without giving some thought beforehand.