There are many types of winter and many winter climates that bees may find themselves in. For the purposes of this blog post, we’re talking about overwintering in the area of the Rocky Mountains in Colorado, USA.

Beehives can be buried under a blanket of snow that insulates the hives, with the bees inside snuggled close to stay warm, hoping to weather the negative temperatures of winter that freeze everything on the other side of the beehive walls.

Honeybees keep their buzz going all winter long, hunkered down to work so they can stay warm. They don’t hibernate or die off—they consume lots of pollen and sweet honey that they stored in summer and autumn—50 to 70 pounds of it—as the snow comes down and the winter extends. Male drones were exiled from the hive in autumn and there aren’t any baby bees in winter, so the queen and her worker bees can take it easy with less mouths to feed.  

Hear the beautiful buzzing from within the hive in this short video just over 3-minutes long:

Even if a beekeeper just keeps a few hobby hives, getting a beehive through a tough winter in a climate like this can be a real hardship. One beekeeper said he couldn’t imagine why a queen bee and her colony would settle here when she could pick a warmer climate where winters aren’t harsh.

The beekeeper doesn't have a lot to do to winterize the hive. S/he might tweak the insulation or ventilation by wrapping a hive in black plastic, so it absorbs the heat of the sun, or play with the size of the hive’s doorway. A beekeeper may also decide to supplement the food source with pollen or sugar water, especially when many queens start to lay eggs again to build up the colony. What mainly keeps the hive warm are the bees and a blanket of snow for insulation.

How do bees stay warm and heat the hive? Once temperatures drop to 40-50 degrees, they group in a cluster and to generate heat they start pumping their muscles, quivering and shaking their wings. With enough bees, they can get the temperature at the center to about 92 degrees, and the queen bee is always at the center. The worker bees move through the cluster, cold to hot and back out again to cold, before heading back in. The bigger the cluster, the better chances the hive’s fate will be a positive one.  

The following video is well worth the 8:37-minutes it takes to watch if you have time:

On a frigid night when it’s 20 below, or maybe even colder, bees on the outer edge literally freeze and fall to the hive floor. Only a hive big enough to endure this loss for many nights will survive.

Honeybees are fastidious about keeping a tidy hive. They don’t defecate indoors, waiting for a warm day to fly outside. When they break out of their warm cluster and fly outside to relieve themselves, one can see small yellow spots in the snow. On a warmer winter day, they’ll fly out to cleanse themselves.

Please remember not to knock on your hive or lift the lid off to see if the bees are alive. If they are dead, it's not going to matter until spring anyway, and if they are alive, chances are you will kill them by exposing them to the elements. Ignore your curiosity and resist the urge to swipe the snow off the top of the hive, for the greater good of the bees you love.

Once it warms up in March, some avid beekeepers dig their bees out of the snow that has literally buried them in a frozen cocoon. At this stage the survivor bees will fly out for relief and to carry out the dead bees. The strange thing is that winter bees can survive 3-4 times longer than summer bees, maybe because the summer bees work non-stop. The lifespan of a summer bee is 4-6 weeks and of a winter bee is 4-6 months. Foraging won’t begin in earnest until dandelions bloom in May.