All About Swarms

Honeybee swarms are an awe-inspiring thing. They let us glimpse into the colony's "hive mind" as it makes its complex decision about when the time is just right to create a new colony. When there is plenty of pollen in the air, plenty of nectar around, and lots of brood and bees in the hives, you know swarm season has arrived.

A swarm of bees spread across two tree branches
Credit: Vcelarstvi Thomayer

The beekeeper has two main concerns when it comes to swarms: catching wild swarms and preventing their own colonies from producing wild swarms. When it comes to catching wild swarms, it's a great way to get some free bees and learn a lot about them in the process. This method of obtaining bees can aid in the goal of propagating strong genetics for local honeybee populations, and we have had the greatest success with bees caught from swarms in our own apiary. We have also found that swarms generally fare much better than bees shipped across the country in packages.

As for preventing swarming, you might ask why a natural beekeeper would want to interfere with a natural process in the bees' life cycle? We do support natural beekeeping, disturbing the colony as little as possible, and generally letting the bees do their thing. However, even the most hands-off beekeeper might have some reasons to consider preventing their colonies from producing wild swarms. For one, a swarm has to go somewhere. If it leaves your apiary and heads to your neighbor's shed or attic, you might find yourself on the receiving end of a sternly-worded text message. Bee swarms have also been known to cluster in public areas, like on playground equipment, while looking for a new home, which can lead to community complaints about beekeeping in general. 

A swarm of honeybees hanging off of a wooden swing
Credit: M. Roth

Controlling swarm behavior can also be a way to look out for the bees' interests, not just the local human community's. Bees that swarm from your apiary can also introduce parasites and disease to wild bees. That is not only bad for the larger bee community, but could come back to bite your colonies later if said parasites and diseases are allowed to go unchecked in the wild and then are brought back to visit your colonies in a stronger form.

What's more, since wild swarms are a prize for beeks and a nuisance for others, someone (you or another beekeeper) is likely going to end up trying to catch the swarm anyway. Why not skip that step by splitting or expanding your current colony before swarming happens?

Catching Swarms

First, let's talk about how to catch a wild swarm. This is arguably the most fun way to get a hive going. It might take a little more work on day one than ordering a package of bees, but those package bees may end up taking a lot more work in the long run, being poorly adapted to your region, having weaker genetics, and not having survived a winter where you live before. (A wild swarm is much more likely to have these characteristics, but there is a small chance you will encounter a swarm of recently imported package bees that escaped from a poorly managed/overcrowded hive or nucleus box, so bear in mind that nothing is guaranteed!). Plus, swarms are free!

Two beekeepers shaking a swarm of honeybees from a tree branch into a nucleus box

While a swarm can seem intimidating, honeybees are actually at their most docile when swarming. They don't have a hive with honey and brood to protect, and they brought as much honey as they could with them in their honey-guts, so they're stuffed. When they're so full, it becomes physically difficult for them to tilt their abdomens enough to sting. “It's almost like doing karate after Thanksgiving dinner. That said, bee behavior is largely determined by genetics. Just like people, some colonies are simply nicer than others!”

Recommended Gear:

  • Veil (or stylish veil)
  • Gloves
  • Cardboard box with ventilation holes
  • Light colored sheet or tarp
  • Pruning shears
  • Bee Brush
  • Lemongrass oil

How to Catch a Swarm

A beekeeper lifting a box up to a swarm of honeybees in a tree
Credit: M. Roth

This is a basic method for catching a swarm on a tree branch. If the swarm is not on a tree branch, these steps can be modified as shown below.

  1. Assess the safety. If the hive is too high or unreachable, or if you would need to be working at a dangerous angle on a ladder, it's not worth it. If it's not a swarm you can reach from the ground, make sure you have help. Don't risk your life for bees. Not every swarm is reachable, and there are other swarms out there.
  1. Place a sheet on the ground where you hope the swarm will land.
  1. Put your box on its side, towards the edge of the sheet. You want the bees to land on the sheet, then crawl into the box.
  1. Put a few drops of lemongrass oil way back in the box to entice the bees in (this mimics the scent from their Nasanov glands).
  1. Cut away any branches, etc. that are in the way.
  1. Shake the bees down onto the sheet.
  1. Let the bees walk across the sheet and into the box.
  1. Wait until after dark, when the scout bees have returned.
  1. Close and tape up the box (or put it in a mesh swarm bag). Leave ventilation holes.
  1. Transport the swarm gently to a safe location for overnight storage.
  1. Install the bees into a hive early the next morning so they don't overheat.

If the bees are on a fence, mailbox, etc., you can spray them with some sugar water (or just water) from a spray bottle so they will be less likely to fly, then use a bee brush to brush them onto the sheet. Try to use as few strokes as possible and keep the cluster together as much as you can. It is also possible to hold a box directly under the cluster and shake the bees into the box. You will almost certainly want help if you try it this way, though we recommend having someone with you any time you are catching swarms.

Any aspiring swarm catcher will likely find these demonstration videos from Paul Kelly of the University of Guelph invaluable:


If you want to catch a swarm, but don't know where to find one, try joining local swarm lists associated with your local beekeeping clubs. You can also give your contact information to your local fire department and pest control agencies. They often get calls for honeybee removal and would rather outsource the job to a local beekeeper than “dispose” of a swarm. Also, inform your friends and family that you are interested in catching swarms. You might find your phone buzzing like crazy before long. We recommend you keep your swarm catching gear in your trunk all spring long to be ready at a moment's notice.

Preventing Swarms

A beekeeper surrounded by flying honeybees, working with a Langstroth hive overflowing with honeybees
Credit: Dieter Ludwig Scharnagl

To keep your colonies from swarming, first you need to understand how and why honeybees swarm. Like all organisms, the honeybee superorganism must reproduce. It does this by sending the queen out with roughly half of the colony (and all the honey they can carry with them) to go find a new home, while the remaining "parent" colony hatches a new queen. This happens just before and during the strong nectar flow in the spring (when bees have the most nectar available to gather from plants in bloom), at the point when the colony has its maximum amount of sealed brood. The bees factor in many variables when deciding whether or not to swarm, and the goal in swarm prevention is to trick them into thinking the time is wrong to swarm (Randy Oliver, Scientific Beekeeping). Since your local plants, weather, and type of bees are all relevant to the question of swarming, this is a great topic to get advice on from your local beekeeping organization.

The way you choose to deal with a colony that is about to swarm depends on your goals and style as a beekeeper. Do you want the most honey possible? Do you want more bees? Do you just enjoy beekeeping and want happy, healthy colonies? Your main options to prevent a swarm are to expand the hive, split the colony, or do both, and you have to consider your beekeeping goals when you decide.


A frame from a Langstroth hive covered up with honeybees and featuring a queen cup on the side
Queen cups (top and right of frame)
Credit: Timothy Paule II

Crowded hives are more at risk of swarming, so expanding the hive space is a common swarm control tactic. In Langstroth hives, this is usually called "honey supering" or just "supering". This involves adding additional boxes of frames, called "honey supers", to the top of the hive to give the bees more space to work. You typically also add a "queen excluder", a thin grate that allows workers, but not the queen, to pass through. This queen excluder goes underneath your new honey supers and prevents the queen from entering them to lay eggs. The result is that these new boxes of frames will end up containing only honey and no brood, hence the name "honey supers". In Warre hives, a similar process is known as "nadiring". Where "supering" refers to going above, "nadiring" refers to going below, so the new hive boxes are placed below the existing boxes in this case. In top bar hives, the bees work sideways, and the beekeeper can simply add more top bars to create additional space. Knowing when to expand basically comes down to regularly checking your hives in the high pollen season and seeing if all or nearly all of the frames/top bars are full of bees. If so, act fast!

While crowding and bee population are the easiest warning signs of swarming for us to see at a glance, they are perhaps not the most important or clearest signs, so we need to look closer to know what's really going on in the hive. In addition to lots of sealed brood, we need to be keeping an eye out for queen cups and queen cells. What are these? A queen cup looks like a little thimble on the frame, but it has nothing inside. It is a bit bigger than a sealed cap of drone brood. The bees make these queen cups to have them handy for when they need to turn one into a queen cell. A queen cell is a queen cup with a developing queen inside. These cells grow larger until they hang off the frame looking like peanut shells.

A close-up of a queen cell
A queen cell
Credit: Franz Schmid

The bees create queen cells for two reasons, swarming and replacing an old queen (supersedure), and we can often tell which type of queen cell is which, so we call them swarm cells and supersedure cells. Clearly, swarm cells are the ones we are concerned with here. These swarm cells often hang off the bottom of the frame, but Tina Sebestyen points out that these can actually be found anywhere on what seems like the "edge" of the comb to the bees, even if that means "in the center of the frame where the comb is not fully drawn,...since to them, it is an edge." Supersedure cells, on the other hand, are more likely to be found on the face of the comb itself. It is worth noting that (as is sometimes recommended) if you destroy every single queen cell in a hive, you may be able to avert a swarm. However, you will likely want to catch and cage the current queen during the process (always a risk to her) and shake the bees off every frame as you go so you don't miss any queen cells. If you miss even one, it will be pointless. Further, you will need to come back and repeat the whole process within 10 days, and again, you cannot miss a single queen cell or the swarm will happen regardless. As such, you might consider other methods of swarm control.

Here is another video from Paul Kelly of The University of Guelph. This one demonstrates how to assess and super a Langstroth hive with a colony about to swarm:

Splitting Colonies

Splitting a honeybee colony is like creating an artificial swarm. For the bees, the result is similar to a natural swarm. They end up with "parent" and "child" colonies, each with a queen, resources, and a place to live. For the beekeeper, the result is largely better than a natural swarm. The beekeeper now has two healthy colonies instead of one and no wild swarm to be responsible for. There are many methods for splitting a colony, but they share a basic idea. Since every colony has different circumstances, you may find it best to take the general idea and adapt it to your needs, or better yet, get advice from experienced folks in your local beekeeping organization.

A beekeeper holding a Langstroth hive frame full of bees. Several Langstroth hives are nearby, and honeybees are flying everywhere.
Credit: Bayanın Gözüyle

In its simplest form, the idea of a swarm control split is to take the current queen and about half of the colony and put them in a new hive to create the child colony, while the parent colony is left with at least one queen cell to make a new queen. It is important to make sure that both the parent and child colonies are ending up with similar amounts of brood and honey. With a Langstroth hive, this might look like taking 5 frames (some brood and some honey) from a 10 frame hive box and transplanting them into a new box. This detailed guide by Rusty Burlew will make the process much easier, and even if you don't use Langstroth hives, it will help you understand the basic idea of a swarm control split. For instance, it would be possible to do this with top bars instead of frames, if you are using top bar hives. You could also take 2-4 Langstroth frames and make a nucleus hive box (nuc). For a Warre hive, the basic idea would be to take the box containing the queen and make a new hive with it, ideally with a large distance (or at least a small distance and a leafy barrier) separating it from the parent colony's hive. However, as there are fewer detailed online resources available regarding Warre hive splits, we would especially recommend seeking experienced help from a local expert in this case.

If you think a swarm might be coming and are trying to decide when is the right time to split,
Tina Sebestyen's guide offers several key signs to watch for:

  1. The presence of "many, many queen cups". You may find queen cups on frames all year, but before swarming there will likely be tons of them.
  1. Lots and lots of drones. If you are seeing both lots of queen cups and lots of drones, Sebestyen recommends going ahead and splitting at this point.

She also lists two more warning signs that can help you if you are feeling unsure:

  1. The queen is losing weight. She needs to be ready to fly with the swarm, so the nurse bees feed her less and "chase and harass her, in essence, forcing her to exercise to get in shape."
  1. Nectar in the brood chamber. While multiple reasons have been suggested, all that is really known is that this is a good indicator of imminent swarming.

Some recommend waiting to split until one or more queen cells have formed. Sebestyen says the "goal is to split the hive before queen cups become queen cells." You may have to experience some trial and error to find what works best for you. It is possible to go too early and end up with chilled brood, and it is possible to go too late and have the swarm still happen. Having an experienced mentor guide you through the process might be your best bet, if you are new to the game.

Other Swarm Control Methods

A beekeeper leans down to work with a Langstroth hive overflowing with honeybees. It sits on a shelf next to two other Langstroth hives which are not overflowing. Bees are flying everywhere.
Credit: Janet van Ommeren

Before wrapping up, let's quickly talk about a few other often recommended methods of swarm control. Requeening colonies after a queen reaches 3 years of age can reduce the risk of swarming (see the below video from Paul Kelly of the University of Guelph to learn more). A young, healthy queen is better able to meet the needs of the colony. A more urgent measure might simply be to remove brood frames (or top bars) from a hive that appears set to swarm. If you are able to put these frames somewhere where the brood can hatch out, you will end up with drawn comb, which is highly valuable. If you have some drawn comb already, you can add frames (or top bars) of it to a swarm-prone hive (perhaps swapping it in for some brood frames) to give the colony more space to work. Using foundation frames will not be effective in preventing swarming, but drawn comb can help a lot.

Few parts of the honeybee life cycle are as intriguing as the swarm. It is a picture of bee democracy in action and a glimpse into the mystery of how organisms can act as a superorganism. Swarms can be tricky to learn about and deal with, but that's all part of the adventure of beekeeping. Good luck with your splits, supers, and swarm catching this season! Be sure to let us know how it's going in the comments and on social media. We’d love to hear from you!

Written by Zak Garland

Featured photo by Andreas Neumann

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