Overwintering: Bee Survival through the Cold Season
Honey bees have developed special skills to overcome the winter in the United States. The bees store their honey and form a cluster in an area where they can stay together to keep warm and easily reach their food. As a beekeeper, it’s important to take some steps to prepare your hives for the winter because, if you don’t, the bees most likely won’t survive—even with their special skills.
A special skill that bees have developed to overcome winter is that they can warm up the hive through thermoregulation. With thermoregulation, the bees keep the whole hive around 59℉. They form a cluster which is like a big ball of bees. You can imagine the cluster like a round watermelon. The watermelon rind would be made up of tightly packed bees that are squished together to keep everyone else warm. Some of the bees on the outside are so cold they can’t even move (but can sting if they are bothered). The inside of the watermelon would be made up of bees that can move around more. They keep the cluster warm because they are moving their bodies and wings. The queen is like the juiciest inside of the watermelon, and the others are taking care of her and doing other bee jobs. If there is brood in the hive, then the cluster will keep them around 94℉. If there isn’t brood, the bees will keep the hive around 70℉.
The watermelon cluster usually starts out in the bottom box of the hive, and they eat the honey on the outside frames. When they eat all of that honey, they move up into the box of honey that they have stored above them. The cluster always has to be touching the honey or else they might be too cold to move out to get the food.
The special skill of the bees to form a cluster helps them live through the winter in lots of different temperatures. A beekeeper can also help make sure the bees are able to put their superpowers to use.
According to Honey Bee Biology and Beekeeping by Caron and Connor, honey bee colonies die over winter because the bees run out of honey, there are too few bees to maintain an adequate cluster, the bees’ digestive tracts compact with too much waste matter or they exhibit Parasitic Mite Syndrome or Colony Collapse Disorder (Caron, 2013).
I wanted to know what beekeepers in Utah do to prepare their hives for the winter. My Mom helped me send a picture on Facebook of me in a bee suit with a sign asking, “What is the most important thing you do to prepare your bee hives for the winter?” We posted it in three beekeeping groups and had 29 people respond. Some people had more than one answer, so we included those too. The beekeepers on Facebook mostly said that treating mites is the most important thing you can do to prepare your hives for the winter. They also said that you need to leave some honey for the bees, insulate them and provide ventilation.
My mom and I agree with the comments from the other beekeepers in Utah and prepare our hives in a lot of the same ways. How I prepare my hives for the winter is: First, we check and treat for Varroa mites. We check for Varroa mites all year long. We check for Varroa mites because we don’t want the bees to be weak going into winter. Varroa mites are a honey bee pest. They feed on the bee brood and weaken adult bees. We treat the hives so there are not as many mites. We have to help treat the mites because the bees can’t do it themselves. They aren’t good at fighting off the Varroa mites, so it is important for the beekeeper to help. The bees aren’t used to the Varroa mites, so they don’t know how to get rid of them easily.
The other thing we do is check the honey and leave a box full of honey over the brood box for the bees. We try to leave 10 frames of honey for the bees. If they don’t have enough honey, they will die over the winter because they don’t get enough food. If we are worried that the bees will eat all of the food they have, we make sugar boards and put them on top of the hive. The sugar board is a mix of sugar and water that hardens, and the bees can eat it all winter.
We also make insulated covers for the bees and paint them black, so the sun hits it and keeps them warm. If we can help the bees to have to work less hard by making the hive a little bit warmer, they will be less likely to die. After that, we put the entrance reducer to the smallest opening it can go. We put the bottom board on to keep the cold air from coming in the bottom of the hive. We don’t worry about ventilation because wild beehives don’t have a top entrance (Seeley, 2019).
On sunny days, we walk out to the hives to see if the bees are flying. We don’t open the hives unless it is warmer than 55℉ and the bees are flying. The bees are coming for cleansing flights, which is when they go to the bathroom (or sometimes they are getting water). We are excited when we see the bees flying in the winter because we know they are still alive.
I love keeping honey bees and think it’s cool they have a special skill to get them through the cold winter. I also like taking care of my bees and want to see them flying to my flowers and garden in the spring and summer!
Caron, D.M. & Connor, L.J. (2013). Honey Bee Biology and Beekeeping. Wicwas Press.
Kearney, H. (2019). QueenSpotting: Meet the Remarkable Queen Bee and Discover the Drama at the Heart of the Hive. Storey Publishing.
Seeley, T. (2019) The Lives of Bees: The Untold Story of the Honey Bee in the Wild. Princeton University Press.
Sanford, M.T. & Bonney, R.E. (2010). Storey’s Guide to Keeping Honey Bees. Storey Publishing.
Walker Bravo, A.D. (March 2020). Personal interview.
Various Facebook Users. (March 2020). Informal online survey with Utah beekeepers.