Bumble bees build a pile of pollen, then mix in honey to make their bread!
What do bees in general get up to in winter time – how do they hibernate?
Although honey bees and bumble bees are closely related, their winter behaviour is very different.
A colony of honey bees will live throughout the entire winter, actively keeping the hive warm and safe. Although a winter colony is much smaller than a summer one when it can hold up to fifty thousand bees, it will nevertheless contain thousands of individuals. They eat and work all winter long—activity which requires a large cache of stored food.
Bumble bees on the other hand do not maintain colonies throughout the winter. Instead, the last brood of the summer colony which might hold up to four hundred bees, will contain a number of queens. Each of these queens will mate and then find a home in which to overwinter, in a hole in the soil a few inches down. Only the queen bumble bees hibernate until spring.
While the bumble bee queen hibernates she is neither eating nor working. Her depressed rate of metabolism allows her to live for long periods while burning very little energy.
In the spring, she must work hard. She begins by finding a suitable nesting spot, then builds a “honey pot” from wax and will use it to hold a small store of honey. She will also collect pollen, and make a pile of pollen mixed with honey called “bee bread.”
Now here is where it gets weird. Much like birds, the queen bumble bee will lay her eggs on the “bread” and then sit on them to keep them warm. During the development of the young bumble bees, the queen will eat the honey she stored in her pot.
The first batch of young bees will be mostly workers—bees who can take over the household chores and the foraging while the queen continues to lay eggs. Later in the season, she will lay some eggs that become queens and drones. These bees will be the ones that are responsible for the next generation, with the drones only living for a few weeks.
This life cycle is found in bumble bees throughout the temperate regions of the world.