Bee Swarming: What It Is and What to Watch for During Swarming Season

by Tiff Willson May 19, 2025

Introduction

Swarming is one of the most fascinating and magical behaviors in honey bee colonies. For beekeepers and nature lovers alike, understanding swarming can help preserve hive health and ensure colony survival. This natural process is how bees reproduce at the colony level and expand their populations in the wild.

What Is Bee Swarming?

Swarming is the process by which a single bee colony splits into two or more colonies. It typically occurs in late spring to early summer when the colony is thriving and resources are abundant.

During a swarm:

The old queen leaves the hive with about 40–60% of the worker bees.
They cluster temporarily nearby while scout bees look for a new nesting site.
Meanwhile, new queens are developing in the original hive to take over leadership.

Why Do Bees Swarm?

Swarming is driven by several factors:

Overcrowding in the hive
Abundant resources (nectar and pollen)
Strong colony population
Queen age or health
Seasonal triggers, particularly rising temperatures and longer daylight

It's essentially how bees replicate their colonies and adapt to new environments.

Signs That a Swarm May Be Imminent

We at Bow to the Bee promote natural beekeeping and honor the process of swarming vs. stopping it from happening in a hive.

Some signs that your hive is going to swarm:

1. Queen Cells

These are larger, peanut-shaped cells usually built at the bottom or sides of brood frames.
They indicate preparation for new queens, often a key sign of impending swarming.

2. Congestion in the Hive

Too many bees in the brood nest or honey supers can cause stress and push the colony toward swarming.

3. Reduced Egg Laying

The queen may slow down or stop laying eggs as she prepares to leave with a swarm.

4. Scout Bee Activity

Bees seen flying around holes, crevices, or cavities outside the hive may be scouts searching for a new home.

5. Bearding

Large groups of bees clustering on the outside of the hive (especially in the heat) could indicate overcrowding or a swarm in progress.

Swarming Season: When to Be Alert

Swarming typically happens:

Spring to early summer (April–June in most temperate climates)
After a rapid buildup of colony strength following winter
During periods of good weather with high nectar flow

In warmer regions, swarming can begin earlier and last longer.

What Should Beekeepers Do?

✅ Allow your bees to swarm!

You can set up a bait box with a lemon balm to attract your swarming bees
Check on your bees more often during this time to catch the swarms
Lemon balm (Melissa officinalis) is considered an excellent natural swarm lure for honey bees because it closely mimics the scent profile of the pheromones bees use to communicate — especially during swarming and nest-finding.

✅ During a Swarm

Observe where the swarm clusters (often in trees, fences, or walls)
Use a swarm trap or gently collect the bees into a box if you're a beekeeper
IF YOU ARE NOT A BEEKEEPER! Call a local beekeeper or swarm rescue service if you’re not experienced. Check Bow to the Bee's list of Beekeepers who will gladly help you with a swarm of bees on your property.

Swarming: A Sign of a Healthy Colony

Swarming is wonderful — it’s a sign that your colony is thriving.

With good hive management and awareness, you can work with your bees’ natural instincts to maintain strong, productive colonies.

Conclusion

Swarming is a remarkable aspect of bee behavior — part survival mechanism, part population expansion. Whether you’re a beekeeper or just someone interested in nature, understanding what causes swarms and how to recognize them can turn confusion into admiration for these complex creatures.