In winter, unlike other insects, honeybees don't go dormant. Instead, they stay awake all winter inside the hive, clustered together in a ball, eating honey, and shivering their flight muscles to generate heat. This is the job of the 'winter bees' - a special caste of bees, born in the fall, and responsible for keeping the colony alive until spring. In this blog post, we'll explain what makes these 'winter bees' special and how they work together to survive the winter.
How do bees get ready for winter?
All summer long, honey bees visit flowers to collect nectar (which they turn into honey) and pollen, both of which they store to eat in the winter. In fact, they are so good at making honey for winter, that they make 2 to 3 times more than they need....which is good news for those of us who enjoy honey in our tea and coffee.
In the fall, the queen bee slows down laying eggs and will stop altogether before winter comes. Before she does, though, she lays a special caste of bees, called the 'winter bees.' These 'winter bees' are physically different from their summertime sisters and have a longer lifespan. They have the special job of keeping the colony alive until spring.
'Winter bees' have an extra large 'fat body'
The ‘winter bees’ are laid by the queen bee in the fall. When they are larva, the winter bees are fed a diet that is scarce in protein (pollen), compared to the summertime bee larva that receive lots of pollen. This pollen-scarce diet causes the winter bees to develop an extra large ‘fat body’ - a special insect tissue that regulates their metabolism and produces vitellogenin, an amazing substance that enhances the bees’ immune system and increases its lifespan. This allows the winter bees to live 6 months instead of 6 weeks. Because of this difference in their physiology, they are considered a separate caste of bees - unique from the other three castes of bees: workers, drones, and queen.
Bees eat honey all winter
Clearly when the ground is covered with snow and the temperatures are below zero, there aren't any flowers to be had. So, honey making is not their thing - that job falls squarely on the summertime bees that spend their time visiting flowers and making honey. Instead, the winter bees are responsible for eating the stored honey and keeping the colony warm by shivering their flight muscles.
To help the bees against the cold, our beehives are given a black insulated Bee Cozy, which provides thermal protection and absorbs some heat from the winter sun. The roof of each beehive is also insulated, so that the warm air that the bees produce doesn't condense on the inner cover and drip back down on them. They have a small upper entrance and lower entrance for air circulation to prevent moisture buildup.
On warm winter days, the bees will fly out of the hive
On mild winter days, when it is sunny, the bees will sometimes fly out of the hive. This usually happens in March, when the daytime temperatures are above zero (maple syrup season).
The bees fly out of the hive, even when there is still snow on the ground, to take 'cleansing flights' to defecate away from the hive. They won't go inside the hive and will wait for warm sunny days. Unfortunately, they don’t always make it back to the beehive and we'll find bees in the snow in front of our hives.
As much as we don't like seeing little bees in the snow, it is a very promising sign of life inside the hive.
Snow is an insulator
Some years, our beehives will get most covered with snow, and this is ok. The snow creates extra insulation for the hives. The heat of the hives will melt the snow around the hive, creating air space. Here is quick video that we filmed a couple winter's ago, in much colder weather.
The bees start getting ready for spring...
Over the course of the winter, the colony gets smaller and smaller as the bees gradually reach the end of their lifespans. In the late winter, the queen will start laying eggs again, in preparation for spring. The queen does this slowly at first, so as to not lay more eggs than the colony can keep warm. The winter bees become responsible for incubating the brood ('brood' is the beekeeper term for developing larva). As the temperatures get warmer and the colony gets bigger, the queen can start laying eggs in larger sections of the empty honeycomb. Come spring, the colony's population will quickly increase, especially as the first flowers bloom and the newly hatched spring bees start bringing fresh nectar and pollen back to the hive.
