Two Reasons to Swarm

Like us, bees need space in which to live their lives. They need a place to raise brood, to store honey, pollen and more. In spring and summer, a colony can expand quite dramatically, both in numbers and in the space needed.  When space starts becoming too limited, bees need a solution.

Their solution is to swarm.

But there is a broader reason why bees swarm, beyond simply needing more space.

When we think of bee reproduction, we think about the queen laying eggs, the adult bees emerging from eggs and so on. This represents reproduction at the level of the individual bee.

When bees swarm, a single colony becomes two. This can be considered reproduction at the colony level and it is an essential element of the way bees live and survive.

Swarming for Space

The most obvious and easy-to-understand reason bees swarm is simply to resolve a lack of space. While this happens in nature when a colony grows beyond the capacity of its home, it is particularly common in the small, purpose-built wooden boxes we call a beehive.

We actually cater quite well for our bees, using structures that we can expand with relative ease. This allows the beekeeper to anticipate the potential for swarms and act accordingly. But that isn’t always possible and bees may eventually swarm.

The basic principle is rather simple and boils down to the following process (somewhat simplified and expanded on further below):

• For whatever reason, the colony decides it needs to swarm
• Future queens are prepared, in queen cups
• Before any new queens emerge, the existing queen and about half of the bees in the colony leave the hive, searching for another home
• The first queen in the old hive will hatch and make sure she becomes the only adult queen
• The remaining bees consider her their new queen
• We now have two colonies, each approximately half the size of the original one, living in different locations

As with anything associated with bees, there is nuance to why and how they do this, but that is the swarm process, in a nutshell.

Swarming to Reproduce

The colony acts, in many ways, as an organism unto itself. The collective “wisdom” of the colony greatly outweighs the awareness or actions of any one bee. Like any organism, the colony needs to survive and is also motivated to reproduce. It is through swarming that the colony reproduces.

The creation of two colonies from one is a natural, positive event supporting the rapid growth of a colony. With a queen in each colony, separate brood-rearing efforts can take place, therefore accelerating the number of bees created collectively.

What Happens During a Swarm

The Decision to Swarm

As we discussed above, some trigger will exist to initiate the swarming intention. In our example, we have a beehive where the colony is starting to exhaust the space available, as it fills frames with brood and honey. So, the colony elects to swarm.

Preparation for Swarming

Queen cups are created by workers on a regular basis. But the queen will not ordinarily lay eggs in them. That changes when swarming is imminent. Her laying an egg in a queen cup illustrates an amazing level of planning – she plans to leave and she is also preparing a queen that will take over from her in the existing hive.

Up until this point the old queen has been laying eggs and is heavy. She isn’t in a position to fly well. Since she will be leaving soon, she needs to lighten up. The workers achieve this by reducing her feedings and she will stop laying eggs. This means there is a gap in the egg-to-adult timeline of the colony.

The Swarming Event

Soon after all this preparation the swarm will start. The queen and 50% – 60% of her offspring will leave. There are usually a few steps to this relocation to a new home.