Understanding and Managing Swarming in Honeybee Colonies

What swarming actually is 🔗

Swarming is a honey bee colony’s natural means of reproduction at the colony level. When the colony grows large enough – or when conditions inside the hive become too congested – roughly half the worker bees leave with the old queen to establish a new home elsewhere. What remains in the original hive is a reduced workforce, all the stored resources, and a set of developing queen cells that will eventually produce a new queen to carry the colony forward.

The process doesn’t happen overnight. Preparations begin weeks in advance: workers build distinctive, peanut-shaped queen cells; foraging slows; and workers deliberately reduce the queen’s food intake so she loses enough weight to fly. When the queen is ready, she exits the hive followed by approximately half the workers, forming a massive cloud of bees before clustering – typically on a nearby tree branch – while scout bees search for a permanent new home.

Why swarming is a problem for beekeepers 🔗

From the bees’ perspective, swarming is a success – the species reproduces and spreads. From the beekeeper’s perspective, it’s a productivity crisis. Around 60 percent of the worker population leaves with a swarm, causing a break in brood production for nearly three weeks while a new queen emerges, mates, and begins laying eggs – both factors that dramatically reduce the foraging workforce and cut honey production.

The original colony can also suffer further through secondary swarms, called cast swarms, where newly emerged virgin queens leave with yet more workers. If these secondary swarms continue, the colony can become severely depleted. Additionally, if the departing swarm clusters on a neighboring property, it can create problems for the beekeeper and surrounding community.

What triggers swarming 🔗

Several factors push a colony toward swarming, but two dominate: overcrowding and the reproductive drive.

Overcrowding 🔗

When too many bees are packed into the hive, there is little or no space for the queen to lay eggs, which triggers the swarm impulse. Poor ventilation can compound the issue, giving bees the impression the hive is already full. As a colony rapidly expands in spring, the brood nest can become congested before the beekeeper has had time to respond.

Queen pheromone weakening 🔗

As a queen ages, her pheromone output decreases – weakening the chemical signals that organize the colony. In an overcrowded hive, even a young queen’s pheromones may be spread too thin to reach the whole workforce. Either situation can tip the colony toward swarming. This is why colonies with queens more than a year old are significantly more likely to swarm than those with younger queens.

Seasonal timing 🔗

European honey bee colonies tend to swarm in early spring, just before and during the main nectar flow – a logical time, as the departing swarm needs abundant nectar and pollen to build new comb, stock food reserves, and raise new brood. The primary swarm season runs from March through May, though secondary swarms can occur later in the season.

Recognizing the early warning signs 🔗

The window for intervention is narrow. Once queen cells are produced, the transition from swarm prevention to swarm control has already occurred – and direct, urgent intervention is needed. Beekeepers should watch for:

• Queen cups and queen cells – enlarged, vertically oriented cells on the face or edges of comb. Their appearance signals swarming preparations are underway.
• Brood on 8 or more frames – a heavily packed brood nest is a classic precursor to swarming.
• Increased drone numbers – a high drone population often coincides with pre-swarm conditions.
• Reduced foraging activity – as swarming approaches, workers reduce foraging and the queen cuts back on laying.

Beekeepers should begin monitoring for these signs about two to four weeks before the main nectar flow begins.

Swarm prevention strategies 🔗

Prevention is always more effective – and less stressful – than dealing with a swarm in progress. The core aim is to relieve congestion and reduce the triggers before queen cells appear.

Providing adequate space 🔗

Providing empty combs in the brood nest and adding supers to relieve colony congestion is one of the simplest and most effective swarm prevention measures. Bees instinctively prefer open space above them. For colonies using two brood boxes, reversing the super positions in early spring – placing the congested upper box on the bottom and the mostly empty box on top – gives bees room to expand upward and relieves crowding.

Regular hive inspections 🔗

Inspections should be carried out every seven to ten days during swarm season, checking for signs of overcrowding and assessing the colony’s readiness to swarm. This frequency matters: if an inspection is left too long and a queen cell is capped, stopping the swarm becomes nearly impossible.

Requeening 🔗

Timely requeening is one of the most effective ways to reduce the swarm impulse. Young queens produce stronger pheromones, which keep the colony better organized and less inclined to swarm. Requeening colonies annually – ideally in late summer when queens are more readily available – is a well-established best practice for swarm-prone apiaries.

Removing queen cells 🔗

Cutting queen cells, also known as “cutting queen cells,” involves inspecting colonies weekly during swarm season and removing all queen cups and queen cells found. This works best when every frame of brood is inspected, with bees shaken off so no cells are hidden – since a single missed, capped queen cell is enough to prompt a swarm. It’s a time-consuming approach, best suited to smaller-scale beekeepers.

Colony splitting 🔗

Splitting a strong colony – creating a new nucleus colony (nuc) from frames of brood, bees, and a queen cell or mated queen – relieves population pressure while also growing the apiary. Research highlights the value of early-spring splits, implemented before the main nectar flow, to prevent swarm preparation during peak foraging periods. The beekeeper essentially does what the bees want to do, but on their own terms.

The Demaree method: keeping the colony together 🔗

Most swarm control methods involve some form of splitting the colony. The Demaree method is different – it controls the swarm impulse while keeping all the bees in a single hive, preserving the full foraging force for honey production. First described by Kentucky beekeeper George Demaree in the American Bee Journal in 1884, the method remains widely used today.

How it works 🔗

In the modern Demaree method, the queen is placed in the bottom brood box with one or two frames of sealed brood, food stores, and empty comb or foundation. A queen excluder is placed above this bottom box, restricting the queen to the lower section while allowing worker bees to move freely throughout the hive. All the open brood from the original hive is placed above the queen excluder – as far from the queen as possible, ideally with honey supers positioned between the excluder and the upper brood box.

This arrangement splits the hive into two functional zones – the queen with flying bees below, and nurse bees with brood above – relieving congestion and suppressing the urge to swarm. The key follow-up step: after five to six days, the beekeeper must return to destroy any emergency queen cells that have formed in the top box – if left any longer, the colony may swarm anyway.

Why it’s effective 🔗

The main advantages of the Demaree method are that it usually stops swarming while keeping a large colony together for a strong honey crop, and it creates options for queen rearing or requeening later in the season. After 7 to 10 days, the beekeeper destroys the emergency cells and either removes the queen excluder to end the manipulation, or repeats the process to extend swarm suppression further into the season.

The main drawback is the effort involved. The Demaree method requires significant physical manipulation, good opportunities to accidentally injure or lose the queen, and considerable heavy lifting. It also requires the beekeeper to locate and identify the queen – which is why many experienced beekeepers recommend marking queens early in the season to make this step far easier.

After a swarm: what to do with the remaining colony 🔗

If a swarm leaves before intervention, the work isn’t over. The remaining colony will have developing queens in their cells. Within days, the first queen to emerge will typically kill her rivals, then take mating flights before beginning to lay – and the colony will gradually rebuild.

After a swarm event, the beekeeper should check that the colony has sufficient stores of honey, pollen, and bee bread to sustain it while the workforce rebuilds, and assess the queen situation – looking for healthy queen cells ready to hatch, or evidence that a new queen is already present and laying. If no queen cells are present or the colony appears weak, requeening with a purchased mated queen may be the fastest route to recovery.

Balancing swarm management with colony health 🔗

It’s worth keeping in mind that swarming is not inherently harmful to bees. For beekeepers who prioritize long-term colony health, allowing occasional swarming can result in a rejuvenated hive with improved disease resistance and productivity over time. The goal of swarm management is not to suppress a natural behavior at all costs, but to align the colony’s reproductive instincts with the beekeeper’s objectives – maintaining a strong, productive workforce through the critical spring and summer months.

The challenge is managing colonies to reach their maximum size right at the start of the main honey flow, while simultaneously keeping them from swarming during that buildup period. Getting that balance right – through regular inspections, adequate space, timely requeening, and techniques like the Demaree method – is what separates reactive beekeeping from genuinely proactive hive management.

What do you think? If a colony is producing queen cells in early spring but hasn’t swarmed yet, would you opt for the Demaree method to preserve the full workforce, or would you split the colony and accept the temporary reduction in honey production? And how do you decide when natural swarming should simply be allowed to run its course?

References

1. https://en.wikipedia.org/wiki/Swarming_(honey_bee)
2. https://bestbees.com/bee-swarm/
3. https://hgic.clemson.edu/factsheet/frequently-asked-questions-about-honey-bee-swarms/
4. https://extension.msstate.edu/publications/maximizing-honey-production
5. https://thewalrusandthehoneybee.com/swarm-prevention-strategies/
6. https://edis.ifas.ufl.edu/publication/IN970
7. https://www.betterbee.com/instructions-and-resources/what-works-to-prevent-swarming.asp
8. https://extension.msstate.edu/publications/colony-growth-and-seasonal-management-honey-bees
9. https://theapiarist.org/swarm-prevention/
10. https://blythewoodbeecompany.com/blogs/news/swarming-honey-bees
11. https://scientificbeekeeping.com/understanding-colony-buildup-and-decline-part-7b/
12. https://en.wikipedia.org/wiki/Demaree_method
13. https://barnsleybeekeepers.org.uk/the-demaree-method/
14. https://thewalrusandthehoneybee.com/demaree/
15. https://www.honeybeesuite.com/demaree-demystified/
16. https://www.blog-veto-pharma.com/en/swarm-management-in-spring/