"What do bees do in the winter?" is a question we are often asked. The short answer is they don't do much...but what little they do is still pretty amazing.
In November, we wrap our beehives for winter and insulate their inner covers. And then we wait for spring, and so do the bees.
Unlike other insects, honeybees don't go dormant in winter. Instead, they ball together in a 'winter cluster' and shiver their flight muscles to stay warm. The cluster moves through the hive slowly eating the honey they have stored for winter. In the fall when we harvest honey, we need to be sure that we leave them with enough honey, otherwise they could starve to death over the winter.
The winter months are hard ones for the bees and there is lots that can go wrong. They are susceptible to a parasite called varroa destructor, which latches on to their bodies for winter and feasts on their fat stores. This parasite also transmits other diseases, like deformed wing virus. Too much moisture in the hive can kill the bees, by dripping cold water from the roof on them and then turning to ice. They can inadvertently back themselves into a corner of the hive and starve, even with a hive full of honey. Or if the colony gets really stressed, particularly after a long winter or during a cold, wet spring, they can get dysentery. In Ontario, roughly 1 in 3 beehives don't make it through the winter, and sometimes the mortality rate is higher.
It isn't until March when we will start to know how the bees fared through winter. When it starts to warm up, the bees will start to fly around - not to find flowers but rather to relieve themselves after holding it all winter! Yellow flecks on the snow is a sign that the bees are alive and well inside the hive. March= time for a bathroom break ;P