You recently fed granulated sugar to your bees, either to supplement their winter stores or to cover an emergency shortage of honey. You figure the extra calories will see them through the cold months. But as you watch them come and go on a warmish day, you see them carry the crystals in their mandibles and drop them in the grass. Why would the bees dump their sugar?
This behavior is not unusual. Everyone who has fed granulated sugar has probably seen it happen, especially when the boards are fresh. Why the bees do it is a good question, but I don’t have an answer. I can only assume they don’t recognize the crystals as food. To them, it’s a piece of junk to be removed from the hive.
Sugar dumping occurs soon after feeding
In my experience, dumping seems most likely to happen soon after sugar is introduced. The format of the sugar doesn’t seem to matter much. It can be granulated sugar, candy board crumbs, or even dry flakes of fondant. If it is hard, dry, and small enough to carry out, that’s what they will do.
Of course, the weather is important too. If soon after you add candy you get some okay-to-fly days, you are more apt to see the sugar come out. If the weather is cold and the bees stay clustered, they won’t be removing anything from the hive because they would get chilled.
Most people who feed hard candy seem to do it late in the year. There’s a “rule of thumb” that recommends giving candy boards after the winter solstice. One reason for waiting is the colder temperatures. If fewer bees are flying, sugar dumping is less likely to occur.
Bees need moisture to eat sugar
Hard sugar needs to dissolve in water before a bee can eat it. In the hive, hard sugar becomes damp on the surface when in-hive moisture condenses on it. The surface layers dissolve and the bees can then lap it up like syrup. This exposes the next layer, which also gets damp and then eaten. As you can see, eating hard sugar is a process that occurs over time.
But when you first introduce a new sugar board or a fresh bag of sugar into a hive, the sugar surfaces are dry and many of the crystals are still discrete. This means a bee can’t eat them, but she can cart them away. As the sugar is exposed to more and more moisture, the crystals begin to dissolve and stick together. Then the bees can no longer remove it.
No-cook candy boards work because you partially wet the sugar, pat it into place, and let it dry. In a day or two, it’s like stone. However, there are always a few grains here and there that didn’t adhere to the main clump, and your bees will carry these away. The same goes for bags of sugar. During the first few days, many grains get removed. But once it bricks together, it takes water or a chisel to break it apart.
How to hasten the hardening of sugar
Some beekeepers hasten the hardening process by squirting the surface of their candy boards or bagged sugar with water. There is nothing wrong with doing this, so if it makes you more comfortable, go ahead and wet it down and then let it harden.
This fall, I’ve gotten more questions than usual about bees dumping their sugar. I believe the reason for this is the erratic weather we’ve had in various parts of the country. What happens is simple. The beekeeper puts a sugar board on because the weather is getting colder. Then, before the sugar has completely hardened, he gets a warm snap. Because the bees are flying and the sugar isn’t yet hard, the bees begin housecleaning. He’s left wondering, “What the?” All that work and they dump it!”
My recommendation is to ignore the dumping. Pretend you don’t see it. Once the cold weather returns and the candy fully hardens, hive life will return to normal. Later, if your colony starts running short on winter stores, you will be gratified to see them feasting on their rock candy mountain.
Honey Bee Suite