Why Do Bees Swarm?
Bees swarm when the colony population grows too large for the beehive. The purpose of swarming is to continue the survival of the species. This phenomenon is called propagation.
Before I get into the details of swarming, let’s start with the basics. To begin with, you have to understand how a bee colony functions.
Inside the colony, every bee has a specific role. These social insects are separated by distinct social classes or castes.
At the top of the ladder is the queen bee. In many colonies, she is the only female in the beehive who is capable of reproducing.
Next, you have the workers. The workers are females, but they often remain sexually immature. They are the largest caste in the colony.
Workers have many responsibilities. They build honeycombs in the hive, feed the queen, and care for bee larvae. They remove corpses of dead bees from the hive, keeping it clean. These industrious creatures are also the ones who handle honey production.
Drones are the only social class made up of male bees. They are produced by the queen seasonally. Drones have a single purpose: to mate with soon-to-be queens.
Queen bees are only born when the colony is sufficiently large. In a small bee colony, if the queen sickens or dies, another queen will be raised by the workers.
Now that we’re clear on the different castes, back to swarming. There are a few events inside the hive that take place before a swarm happens.
The first is the rearing of future queen bees by the workers. This occurs when there are not enough cells inside the beehive for the queen to lay her eggs. When this happens, the workers take action.
A small group of larvae is selected by the workers. Rather than feeding them as they do all the other larvae, these future queens are given special treatment.
Workers feed them royal jelly. This is a secretion only worker bees are capable of producing. It is only fed to the queen and future queens.
The workers also adapt the cell these larvae are in. They are enlarged to allow these females to develop into queens, who are larger in size than workers.
The male drones are also produced during this period. Once they reach maturity, they stay inside the hive. They wait in anticipation for the time of their mating flight. Aside from mating, drones do little around the hive at this time. They feed off the colony’s honey stores, request food from workers, and rest.
Activity in the hive will continue as normal as the young queens grow. The only change is that worker bees start traveling various distances to look for a new hive location. These workers (known as scouts) will check surrounding areas for viable homes. This way, the swarm will have somewhere to go when the time comes.
Bees are able to communicate just as well as we can. Once a new home is found by scouts, they share it with the other workers.
This is done through a combination of pheromones and dancing. By the time the swarm is in the air, all the workers know where they’re heading. When the new queens are ready to emerge, the time for swarming has come.
What Happens During Swarming?
Right before the future queens reach maturity, the current queen leaves the hive. The majority of the hive’s occupants will go with her. Only a small group of workers stay behind to maintain the hive. A battle for queenhood is about to begin.
The first young queen to come out of her cell is the luckiest. She will immediately start destroying the cells of the other virgin queens.
If more than one queen emerges at the same time, they will fight. The surviving queen is the one who will start the new colony in the old hive. Surviving virgin queens leave to begin their own colonies.
Meanwhile, the swarm consisting of the original colony is out in the open. These swarms can consist of large numbers, from 5,000 to 20,000 bees.
Most of the swarm is worker bees, although drones can be included too. All the bees surround the queen to protect her during flight.
Queen bees can’t fly as well as the workers and drones. Whenever the queen needs to take a break, all the other bees do the same.
The swarm will pack tightly around her to keep her safe. When the swarm isn’t in the air, it’s called a swarm cluster.
It can happen that bees don’t find a new home site before the swarm leaves. If this is the case, scouts will leave the swarm behind to explore.
Once a suitable place is found, the scouts will lead the swarm to it. Bees like to construct their hives in sheltered locations, like hollow trees.
Unfortunately, there are man-made items that can be attractive nesting spots too. These include under decks, in utility boxes, or outbuildings like sheds.
In the worst-case scenario, bees will start nesting in locations that are less than ideal.
This is when you may see bees building a hive with beeswax in odd locations. For instance, they can settle on the side of your home or on an exposed tree limb.
Exposed colonies have lower survival rates. Predators like birds and reptiles can easily target the bees.
Are Bee Swarms Dangerous?
In general, bee swarms are not a danger to humans. Don’t forget that the bees are focusing on getting to their new home. They are eager to start building a hive and getting settled. Out in the open, the bees are vulnerable to predators.
Make sure that the swarm you’re seeing is actually bees. These insects can be confused with hornets, wasps, or yellow jackets.
Wasps and hornets have more pointed rears than bees. The average honeybee is roughly three-quarters of an inch long.
Yellowjackets, although they look similar, are up to half an inch long. Wasps are also more vivid in color, with clear yellow and black rings.
You want to stay well away from swarms of the latter types. All three of these flying insects can sting repeatedly and could be aggressive.
It can be disconcerting to see thousands of bees in one place. Still, there’s no need to be frightened. That isn’t to say that you shouldn’t be cautious. Not all bee swarms are alike—some species are more temperamental than others.
Obviously, one thing you should never do is deliberately provoke the swarm. Don’t spray the bees with water or throw things at them.
First of all, honeybees are vital for pollination. Certain crops wouldn’t exist if bees suddenly became extinct. There aren’t as many colonies out in the wild anymore. You shouldn’t kill bees unnecessarily.
Next, you could end up badly injured. If you harass the bees enough, they’re likely to come after you and sting you.
There is a point after swarming when bees do become dangerous. That is when the colony settles down and the queen lays her first batch of eggs.
This is why it isn’t wise to destroy a beehive on your own. Call a professional to have the bees safely removed.
Warning Signs Before a Swarm
As I’ve established, bee swarms aren’t typically something to be worried about. Despite that, it’s useful to know the warning signs before a swarm.
Unless you’re a beekeeper, knowing when a swarm will occur is tricky. Most of the pre-swarm signals happen inside the hive.
Even if you know where a beehive is, you won’t be able to see inside it. You can’t know when the immature queens are nearly grown, for example.
There are other indicators you can keep in mind, though. Bees only swarm when the weather is warm—late spring to early summer in most regions.
The swarm will time departure from the old beehive during the warmest hours. Usually, this is in the middle of the day when the sun peaks.
Can You Prevent a Swarm From Happening?
Preventing swarming in wild honeybees is unwise and nearly impossible. Beekeepers prevent swarms from happening for the benefit of the colony.
When bees swarm, they exhaust their honey supplies. Plus, the colony leaves the beehive behind. Neither of these is good for beekeepers.
To prevent swarms, beekeepers make sure there’s adequate space in the hive. If the queen has enough room to keep laying her eggs, swarming isn’t necessary.
The beekeeper will also ensure the colony doesn’t get overcrowded. This is done by dividing the colony when it grows too large.
De-queening (removing queens) is a last resort measure to stop swarming. This is only done when immature queen cells have already formed. Beekeepers will endeavor to avoid this from happening at all.
Bee swarms are harmless in most cases. Enjoy observing the swarm from a safe distance and leave it alone.
If you can’t identify the insects as bees, stay well away from them. Swarming bees may not pose much of a danger to you, but similar-looking insects, like wasps, do.