Many species of insects escape the cold temperatures of winter by migrating or hibernating. But what about honeybees? You don’t see them very often, if at all, when it’s cold. So where do they go, and what do they do, in winter?
In winter, honeybees don’t actually go anywhere. They overwinter inside their hive. They don’t migrate or travel very far away – in fact, they rarely leave their hive for any reason during winter.
When weather conditions are harsh, bees don’t even go outside to poop – instead, they hold in their waste until the weather changes, when they make special cleansing flights.
Honeybees build up enough food in spring to last throughout the colder months. That means they don’t need to leave the hive to collect pollen or nectar during winter.
Honeybees instead spend the majority of winter clustering together inside their hive, vibrating their flight muscles to keep warm.
Do Honeybees Hibernate In Winter?
Contrary to what some people believe, honeybees do not hibernate.
Hibernation is a way certain animals and insects conserve energy to survive difficult weather conditions. Animals that hibernate conserve energy by making physiological changes, such as slowing their metabolism or lowering their body temperature.
Bumblebees, for example, hibernate during winter. The last of the brood laid before winter will contain a number of new queens.
These queens will mate, then find a safe place to hibernate. All drones and workers will die off.
The newly mated bumble queens will find a suitable spot, dig a hole in the ground and burrow down about 4 inches (10 centimeters). They will remain in the ground for months, reducing their metabolic rate to conserve energy.
Unlike bumblebees, honeybees don’t hibernate. They instead overwinter, which means they maintain an active colony throughout winter.
The number of bees inside the hive reduces in winter, as the queen generally stops laying eggs towards the end of fall (autumn). Male bees (drones) will die off, leaving only the queen and worker bees.
Despite this drop in numbers, there are still thousands of bees inside the hive during winter. These bees do not lower their metabolic rate or undergo physiological changes to conserve energy.
In fact, while they rarely leave the hive during winter, they are highly active inside, forming a cluster and vibrating their flight muscles to keep the colony safe from the cold temperatures outside.
As such, you’ll actually see an increase in the metabolic rate of honeybees during winter, rather than the decrease that’s typical in insects or animals that hibernate.
What Do Bees Do In Winter?
In winter, honeybees stay in their hive. They use different methods to control the internal temperature, helping them to withstand the cold temperatures outside.
This is especially important to take care of the queen. The queen is essential as she will repopulate the hive in spring. If the queen dies, it could mean the extinction of the colony.
The main method of temperature control used by honeybees is the formation of the winter cluster. Honeybees huddle together in a big group, contracting and loosening the cluster to regulate the temperature inside the hive.
Bees typically begin forming this cluster when temperatures reach about 65° Fahrenheit (18° Celsius). As the temperature drops further, bees move closer together, contracting the cluster. The tighter the cluster contracts, the less heat can escape.
There are generally two layers to the winter cluster:
- An outside shell, with bees remaining side by side, facing inwards.
- An inner layer where bees are able to move about freely.
In the inner layer of the cluster, bees vibrate their flight muscles to increase their body temperature. By doing so, they can increase their temperature by around 50° Fahrenheit (10° Celsius). This helps to keep other bees inside the cluster, as well as brood, warm.
The outer layer of the cluster acts as insulation. Bees in this layer form a tight ring, using their bodies as a shield to stop heat created by bees inside the cluster from escaping.
Bees will take turns moving from the outer layer to the inner layer, where they’ll often remain for about 12 hours, vibrating their flight muscles to increase their body temperature whenever it drops.
What Do Bees Eat In Winter?
Vibrating their flight muscles to keep warm takes up a lot of energy. For that reason, worker bees will consume a lot of honey during winter.
They will take breaks from the winter cluster, temporarily leaving to eat honey stored in other areas of the hive. After eating honey, bees will return to the cluster and continue working to keep the hive warm.
If temperatures are too cold, a colony can still die of starvation even if they have sufficient honey levels. This is because bees are unable to leave the cluster and reach honey on the outer edges of the comb.
Because bees eat honey during winter, it’s important for beekeepers to leave sufficient amounts inside the hive. Without enough honey, a colony could perish.
Bees Work Hard To Keep Brood Warm In Winter
In the early stages of winter, as well as the months leading up to winter, the queen bee will stop laying brood.
In mid-winter, however, the queen will restart her egg-laying so the colony has enough new workers to collect pollen and nectar throughout spring.
The cluster plays an important role in keeping the new brood warm. If the temperature drops too low, it can affect the health of the emerging adult bees, including their susceptibility to pesticides, wing development, learning ability, and even their color.
Bees form layers around the brood to maintain the temperature at optimal levels. Individual worker bees will press their bodies onto capped brood cells that contain pupae and vibrate their flight muscles to pass heat through.
Other workers will place themselves inside empty cells and use the same vibration technique to heat up the cells surrounding them.
Using these techniques, honeybees are able to maintain a temperature in the brood area of the hive between 34°-36°C (93°-97°F). This allows for the healthy development of adult bees to emerge in time for spring.
Colonies Raise ‘Winter Bees’ To Help Them Survive Winter
Another thing bees do to help the colony survive winter is to raise ‘winter bees.’ This happens in late fall (autumn) as the weather starts to turn cold.
Winter bees are essentially worker bees with larger abdomens. Their fat bodies – a section of tissue that contains lipids, glycogen, triglycerides, and some proteins – produce a substance called vitellogenin.
Vitellogenin enhances the immune system and increases lifespan. It is produced by queen bees and is one of the reasons why they live so much longer than workers.
Worker bees raised during the majority of the year have no vitellogenin present. However, winter bees do, which helps them live such unusually long lives.
Normally, worker bees live for between 15-38 days. This is why a queen bee has to constantly lay new eggs throughout the year – to replace the bees that die.
However, winter bees can live for 150-200 days, long enough to help the colony survive throughout winter. This means the queen can stop laying eggs for a few months during winter without threatening the survival of the colony.
As spring approaches, the queen will start to lay new eggs, which will soon replace the winter bees. The new bees that emerge in spring will not produce any vitellogenin, and therefore not live as long as the winter bees.
Why Don’t Bees Go Anywhere In Winter?
Bees have developed such effective methods of surviving cold weather that they don’t need to go anywhere during winter. They can instead remain in their hive throughout the year.
During winter, bees eat this honey to give them enough energy to survive, so they don’t need to forage for food.
In winter, there are typically fewer flowers in bloom too, which makes it harder for bees to find pollen and nectar. Plus, the cold weather makes it dangerous for them to leave the hive.
If they reach levels outside their tolerance, they can fall into a chill coma and die.
When Do Bees Leave The Hive In Winter?
Bees generally don’t leave the hive during winter unless it’s for a cleansing flight (to release waste). Otherwise, they will stay inside until the weather becomes warm enough for them to forage for food.
According to one study, honeybees stop leaving the hive when temperatures drop to about 50° Fahrenheit (10° Celsius).
They stay inside the hive until temperatures warm up again, to around 60.8° Fahrenheit (16° Celsius). That’s when they will start flying outside again to forage for food.
It’s important to note that this study was done in a subtropical environment. Certain subspecies of honeybees may have adapted to different climates and can have a varying level of activity during these temperatures.
Generally speaking, though, once temperatures are warm enough that bees aren’t needed to be part of the winter cluster, they will leave the hive.
Honeybees are incredible creatures who have developed many methods of survival to withstand harsh conditions. There is no better example of this than their behavior during winter.
Rather than hibernate, migrate or leave the hive, honeybees will stay inside and work together to survive. The formation of the winter cluster can ensure the colony, including the queen, lives throughout winter and is able to repopulate during spring.
Winter is a challenging time for bees, but a strong colony has the ability to withstand very long and cold winters.