What is a Swarm?

A swarm of honeybees is distinctive. The swarm in flight can be described as a cloud of bees flying excitedly. The swarm then gathers into a brown mass of thousands of bees clustered tightly together.

Honeybees are unusual in that they overwinter as a colony. As the days lengthen and the temperature starts to rise, the queen bee will start to lay eggs at an ever-increasing rate to build up the colony’s strength.

The colony will quadruple – or more – in size and their instinct is to ‘swarm’. This means that the queen will leave, accompanied by half of the worker bees, in search of a new home. The remaining bees are left with a few developing young queens and the wherewithal to rebuild their colony. Here, you see a ‘queen cell’; inside is a new queen. She will emerge in the next few days to take her departed mother’s place.A frame of brood with queen cells

The swarm will fly a short distance then settle in an easily-recognisable cluster while they decide what to do next. This can be anywhere such as a branch, a soffit, a chimney, a shed roof, a bicycle, a ladder – there is no limit to their sense of adventure.

You will see quite a lot of activity around the cluster, scout bees flying to and fro then reporting back about suitability of various potential new homes. Sometimes they will decide within a few minutes, occasionally it can take days.

When a consensus has been reached they take to the skies again and head for their new home. Once they have started to build comb and the queen has started laying eggs again, they are no longer a ‘swarm’; they are a colony.

Beekeepers are keen to collect swarms for 2 main reasons:

  • the bees’ concept of an ideal home can sometimes be at odds with humans’. If they settle in a roof space, a thatch, an outbuilding, or anywhere inconvenient it can be difficult and costly to remove them; such removal is often outside the beekeeper’s capability for reasons of insurance as well as health and safety
  • a swarm taken by a beekeeper will be given a good, clean, safe new home. It will be checked for diseases and will be fed appropriately until established. A swarm settling as a feral colony may chose a poor site, the weather may prevent them from foraging, or they could be carrying significant loads of Varroa mites

Swarming was strongly encouraged in Medieval times when the saying ran:
“A swarm of bees in May is worth a field of hay
A swarm of bees in June is worth a silver spoon
A swarm of bees in July is not worth a fly”

In those days, honeybees where kept in ‘skeps’ – woven baskets – and the only way to harvest honey was to kill the bees – an appalling thought nowadays! Therefore, encouraging the bees to make new colonies made sure that the beekeepers would still have bees to overwinter and start again next year. A swarm in May would build up well, whereas a swarm taken in July would struggle to reach a size that was capable of surviving winter.

Now, of course, we have hives that are cleverly-designed, being the right shape for a colony of bees and allowing us to harvest any excess of honey that they might store (only the excess – it would be counter-productive to take more than they can readily spare).

Every effort should be made to preserve honeybees as they are under threat.