What Do Honey Bees Do in Winter

Our first year of beekeeping, we were so busy with all of the chores and newness of having bees that we didn’t stop to think about what happens to bees during the winter.

What do honey bees do in winter? When winter temperatures drop below 50° F, it is too cold for the bees to fly. In the hive the bees mass together around the queen to form what is called the winter cluster. They vibrate their flight muscles to generate heat up to 95° F in the center of the ball. They eat the honey and pollen that were stored during summer and autumn.

There is a lot that goes on in the hive leading up to and during the winter, so continue reading to find out more.

How Do Honey Bees Keep Warm in the Winter?

An unusual thing about honey bees is that they are one of a few insect species that can generate body heat, and not just a little.  They accomplish this by flexing their flight muscles. 

A bee can fly in temperatures in the 50’s Fahrenheit, because it is keeping itself warm.  The wind passing over its body as it flies can cool the bee too much, so it can become sluggish.  The bee may land and pump its flight muscles to warm up again. 

They need to keep their flight muscles at 85 degrees or higher or they won’t be able to fly.  At takeoff, their flight muscles reach nearly 100 degrees. If the bee becomes too cold and/or runs out its thirty-minute supply of stored body fuel, it won’t be able to get back to the hive.

Inside the hive, honey bees still use their flight muscles to maintain hive temperature. The connection between wings and flight muscles in the thorax is disconnected. The bees then rapidly flex or shiver their muscles to keep the high temperatures needed in the hive during cold weather.

There are three reasons to keep winter hive temperatures high.

The queen bee is essential to the hive. Worker bees may make all of the decisions for the hive, but it is the queen who lays the eggs and ensures the survival of the colony.  

Brood, un-emerged baby bees, are the future of the colony. Although the queen doesn’t lay eggs during most of the winter, she does begin in early spring. These are the nurse bees and future foragers for the hive.

If the temperature inside the hive falls below 40 degrees, all the bees will die.

How Do Bees Survive Winter?

So, the bees have a heating system.  Now what?

During the fall, the worker bees have been hard at it, storing honey and pollen for their food supplies for the winter.

As temperatures begin to drop, the worker bees push out the drones, the male members of the hive. The sole responsibility of drones is to mate with queens from other colonies during the spring and summer. They don’t even feed themselves. The worker bees feed them. Because they are nothing but a needless expenditure of food and energy during a time of stress to the colony, they are removed from the hive and aren’t allowed to return.

As temperatures drop into the low 50’s, the bees begin to form into a ball in the middle of one of the brood boxes in the hive.  As temperatures continue to drop and the foragers stay indoors, the bees all cluster around the queen to keep her warm. Bees will go into empty cells in the wax comb to make the cluster. This way they can make as tight a ball as possible.

The center of the cluster will be from 85 to 95 degrees.  It is around 85 degrees when the queen is in the center. When there is brood as well as the queen, the workers heat up the cluster to around 95 degrees.  The edges of the cluster will be around 48 degrees.

An individual bee can generate up to 110 degrees of body temperature. The bees making the heat have been dubbed “heater bees”. The ones on the outside of the cluster are at much lower temperatures and begin to get sluggish. They are an insulation layer for the bees deeper within the cluster.  As they get cooled, they migrate toward the center of the cluster and warmer bees become the outside until they, too, become cool and move inward. 

During warmer days, the bees will move around within the hive. They will shift to be closer to honey frames. If the weather remains very cold, the bees might stay in one place. It can starve with honey frames only a few inches away.  We saw this with some of our hives after our first winter. There were full frames of honey with a dead cluster of bees just a few frames away. 

During winter months the bees feed on the honey and pollen that they stored during the summer and fall months.  The more food in the hive and the closer to the cluster, the better.  If a colony gets chilled, it will be too sluggish to reach honey stores just a few frames away. 

Bees don’t need an external water source during the winter.  Because everyone is in the hive and creating a lot of heat, humidity can build up in the hive. This provides enough moisture for the bees. In fact, too much moisture in a hive can kill a cool colony in the winter.

Bees do need potty breaks during the winter. They will stay confined for long periods, but on sunny days when the temperature of the hive rises, the bees will take what are known as cleansing flights to relieve themselves outside of the hive.

How Do You Take Care Of Bees In The Winter?

As I mentioned, during our first year of beekeeping, we had plenty to keep us busy.  Then winter arrived.

We had a whole new learning curve with new terminology, new chores, and new equipment.

The winter process begins in the fall. The steps are:

  • fall feeding
  • combining colonies
  • moisture control
  • winter feeding
  • mite control

Fall Feeding

During the fall, after removing the honey supers (boxes of honey for the beekeeper), it’s important that the bees have enough honey stored in the brood boxes to keep them fed through the winter.

A hive will need 60-80 pounds of honey to get through the winter.

If there is what is known as a period of dearth, when not many plants are providing nectar and pollen, the bees may begin to eat the honey they have already stored.  One year we found virtually all the honey frames empty at the beginning of September.  This is when beekeepers need to feed their bees so they can store enough honey for winter. 

Combining Colonies

There is a fine line that divides colonies that can survive the winter from those that can’t. Large colonies can create enough heat to keep the hive warm.  But they require a lot of food.  Smaller colonies don’t need as much honey and pollen stores, but with fewer bees, they will have a more difficult time keeping the hive warm.

I wish we had known more about this that first year.  We had two colonies that were small.  The appropriate steps would have been to decide upon the best queen of the two hives, kill the other queen, and then combine the two hives to make one.  We would have had a chance of one surviving the winter.  As it was, we lost two.

Homemade Quilt Box for Moisture Control

Moisture Control

Hot bees in a confined space will create a lot of moisture.  Bees can tolerate cold much better than wet. There are two problems with damp.  It can cool and chill the bees.  It encourages the growth of mold, fungi and other unpleasant things. Think of a damp, cold bathroom in winter. 

Here in the Pacific Northwest, our winter temperatures are mostly in the 30’s and 40’s. Instead of snow we get rain.  Moisture is a big problem in the bee yards, so the quilt box is a standard piece of apiary equipment.  No, a quilt box has nothing to do with patchwork blankets.

A quilt box is a wooden frame 2”- 4” deep that fits on top of hive boxes. Screen covered vents for air circulation are all along the sides near the top. The bottom is either wire mesh with fabric or just firmly attached fabric across the bottom of the box.  The contents of the box vary, but the intent is the same – they should be able to soak up excess moisture, so it won’t drip into the brood box and onto the bee cluster.  Some people use wood shavings and some use burlap bags for filler.

We have hamster bedding in our quilt boxes.  We can lift the lid and stick our hands in to check the moisture level without letting air into the hive.  If the bedding seems too damp, we scoop it out and put in dry. The box of old shavings gets set in a corner in the kitchen to dry out.

Winter Feeding

The girls (the bees) may eat up their honey stores and need to be fed.  This is where the candy board comes in.  It is a 2” high wooden frame with wire mesh on the bottom and the bee food is set into the frame on top of the wire.

During the winter, bees are fed solid food because syrup might freeze.  There are several methods of feeding sugar during the winter.  Some people cook sugar cakes to make bee fondant. Some make cakes without cooking them. And some people just use granulated sugar, either sprinkling it on top of the frames or setting a small bag of sugar on top and slicing through the paper.

Varroa Mite Treatment

The Big Bad for bees is varroa mites. They weaken bees, making the bees more susceptible to diseases.  Varroa mites lay their eggs in open brood cells and attach themselves to any baby bees that are laid there.  Winter, when most brood cells are empty and uncapped, is an excellent time to treat with oxalic acid vapors.  Fogging hives once a week in January will ensure that all cells have been treated.  This gives your bees a good, mite free start going into the spring population build-up.

It may sound as though there is a lot to do to keep your bees healthy and happy during the winter, but it takes little time and you are rewarded by seeing your “girls” coming out of hives in spring.

Related Questions

How many bees die in winter?

When going into winter, a hive may have 60,000 bees.  Easily two-thirds of those could die over the winter. Many of those will just succumb to old age.  Even with 20,000 bees, a hive will have a healthy start for spring.

Can you move a beehive in the winter?

Yes. It is easiest to move beehives in the winter because the bees aren’t going out of the hive and flying.  Block up the entrances and move the hives. Professional beekeepers in the far north will sometimes move their hives into large storage buildings for the winter