Swarming is among the most captivating behaviors in honey bee biology. It is nature’s mechanism for colony reproduction and survival, ensuring genetic diversity and the spread of bee populations. For beekeepers, however, swarming often translates to loss of workforce, reduced honey yields,
and management challenges. Understanding its causes, recognizing warning signs, and applying timely control measures are vital for productive and sustainable beekeeping.What Is Swarming?
Swarming is the natural process through which a colony divides into two or more new colonies. The old queen leaves the parent hive accompanied by thousands of worker bees to establish a new nest, while the remaining bees rear a new queen to continue the parent colony.
Thomas Seeley (2010) describes swarming as the reproductive cycle of the “superorganism.” Rather than individuals reproducing, the colony as a whole multiplies. It generally occurs during favorable seasons of nectar abundance and mild temperatures, often coinciding with the main honey flow. While it signals a strong, healthy colony, unmanaged swarming disrupts foraging, halts brood rearing, and can cut honey harvests dramatically.
Causes of Swarming
Swarming behavior is influenced by a combination of biological, environmental, and managerial factors.
1. Congestion
Overcrowding within the brood nest limits space for the queen to lay eggs and for workers to store nectar. Once congestion persists, workers construct queen cups that develop into swarm cells.
2. Queen Age and Pheromone Decline
As a queen ages, her production of queen pheromone—which keeps the colony unified—declines. When pheromone concentration drops below a threshold, workers begin rearing new queens. The old queen, often slimmer from reduced feeding, departs with part of the colony to form a swarm (Winston, 1991).
3. Seasonal Stimulus
Lengthening days, warm temperatures, and abundant forage stimulate brood rearing and wax secretion. Population growth accelerates, and without timely expansion of space, swarming becomes inevitable.
4. Genetic Factors
Some bee races, particularly Apis mellifera scutellata and other tropical strains, are naturally more inclined to swarm (Bradbear, 2009). Selective breeding for moderate temperament and reduced swarming tendency forms part of modern apicultural improvement programs.
5. Poor Ventilation and Heat Stress
High humidity and heat inside the hive trigger bees to cluster outside (bearding). Persistent overheating or insufficient airflow often leads to swarming as colonies seek cooler nesting sites.
Stages of Swarming
- Queen-cell construction: workers build large, peanut-shaped cells along comb edges.
- Larval feeding: selected larvae receive only royal jelly, ensuring queen development.
- Queen slimming: the old queen’s feeding reduces, making her light enough to fly.
- Scout searching: foragers identify suitable nesting sites within several kilometers.
- Departure: the swarm leaves with roughly half the colony’s population, clustering temporarily on nearby vegetation before relocating.
Crane (1990) notes that the primary swarm usually departs a day or two after the first queen cells are sealed. If several virgin queens emerge later, smaller “afterswarms” may follow, severely weakening the parent hive.
Recognizing Warning Signs
- Numerous sealed or developing queen cells along frame bottoms.
- Reduced egg-laying and visible congestion in brood areas.
- Idle bees clustering at the entrance or under the hive.
- Distinct low-pitched buzzing, especially during warm afternoons.
Early detection allows corrective action before the swarm departs.
Consequences for Productivity
Uncontrolled swarming divides the workforce and interrupts brood continuity. The parent hive must raise a new queen, resulting in at least a three-week brood gap. The new swarm, meanwhile, must construct comb and raise brood before collecting surplus nectar. Research summarized by Winston (1991) indicates that a single swarm event can cut honey yield by 40–60 percent.
Preventing Swarming
Although swarming cannot be completely eliminated, good management significantly reduces its occurrence.
Provide Adequate Space
Add supers or brood boxes as soon as nectar flow begins. Ample space allows continuous egg-laying and storage, reducing crowding.
Requeen Regularly
Replace queens every one to two years to maintain strong pheromone levels and steady brood production. Young queens are less swarm-prone and improve colony uniformity.
Equalize Colony Strength
Transfer brood or bees from strong to weak colonies to balance populations and relieve pressure in congested hives.
Split Strong Colonies
Making nucleus colonies from large hives simulates natural swarming under beekeeper control. It prevents loss while expanding apiary numbers.
Improve Ventilation and Shading
Ensure hives have adequate entrance openings, screened floors if available, and partial shade during hot months to avoid thermal stress.
Conduct Regular Inspections
Weekly checks during buildup seasons allow removal of swarm cells and correction of root causes. The FAO (2009) emphasizes that simply cutting out queen cells without reducing congestion fails to prevent swarming.
Managing an Active Swarm
Capturing a Swarm
When a swarm clusters nearby, shake or brush it gently into a ventilated box or prepared hive. A light mist of water calms the bees. Keep the captured swarm in a shaded place until evening before installing it in a permanent hive.
Confirm that the queen is included—fanning behavior at the entrance indicates her presence. Without her, the swarm will abscond within hours.
Managing the Parent Hive
Inspect the original colony soon after swarming. Leave one or two healthy queen cells and destroy the rest to prevent afterswarms. Feed lightly to stabilize remaining bees. Once the new queen emerges and begins laying—typically within three weeks—the colony will rebuild strength rapidly.
Artificial Swarming Methods
Artificial swarming mimics natural swarming while keeping control of both bee groups. One reliable approach is the split method. Move the old queen and two or three brood frames with adhering bees into a new hive placed near the original. Flying bees follow the queen to the new hive, easing pressure in the parent hive. The parent colony rears a new queen and remains productive.
Seeley (2010) notes that controlled artificial swarming supports both colony survival and yield because it maintains balanced populations across hives.
Long-Term Strategies
- Selective breeding: propagate queens from colonies with moderate swarming tendencies and high productivity.
- Hive spacing: avoid clustering hives too closely; this reduces drifting and overheating.
- Forage continuity: encourage staggered flowering by planting nectar-rich species such as Calliandra, Croton, and Acacia.
Bradbear (2009) emphasizes that balanced nutrition and genetic stability create calmer, less swarm-prone bees.
Ecological Role of Swarming
While beekeepers aim to minimize swarming, it plays a crucial ecological role. Swarming enables bees to colonize new habitats, pollinate wild flora, and maintain ecosystem diversity. Responsible management therefore seeks balance—limiting economic losses while respecting bees’ natural reproduction.
Conclusion
Swarming is both a challenge and a marvel of nature. It demonstrates the colony’s vitality but, if unmanaged, undermines productivity. Successful beekeepers learn to read early warning signs, provide adequate space, maintain young queens, and intervene gently through splits or artificial methods.
By combining biological insight with practical management, apiarists align human goals with bee instincts—achieving productive, stable, and ecologically balanced apiaries.
References
- Bradbear, N. (2009). Bees and Their Role in Forest Livelihoods. FAO Forestry Paper 171.
- Crane, E. (1990). Bees and Beekeeping: Science, Practice and World Resources. Cornell University Press.
- FAO. (2009). Honey Bee Diseases and Pests: A Practical Guide. Food and Agriculture Organization of the United Nations.
- Seeley, T. D. (2010). Honeybee Democracy. Princeton University Press.
- Winston, M. L. (1991). The Biology of the Honey Bee. Harvard University Press.