© Swarming or at least the preparation to swarm is a natural part of the honey bee colony life cycle.
It is important when inspecting combs for signs of swarming that they are searched thoroughly.
Queen cells are easily hidden by bees and can be easily missed so this normally means that bees must be moved out of the way to give a clear view of the comb.
This can be done with a little smoke or simply by blowing on the bees or by slow gentle shepherding with the fingers or bee brush.
If the queen is seen she should be temporarily caged for safe keeping until the inspection is over.
Note that the presence of queen cells does not necessarily mean that the colony is preparing to swarm.
Possibly the colony is preparing to supersede their queen, meaning that the new queen will replace the old queen without swarming.
It is also possible that the queen cells were made in an emergency to replace a missing queen (for example, lost or killed during an inspection).
It is difficult to differentiate the reasons for queen cell production so unless the reason is known, it is best to assume that they are a preparation to swarm.
Empty queen cups can be present throughout the season but are not a sign of swarming though they must all be checked to see if they contain eggs or developing larvae.
Queen cups containing just eggs are not a sign of swarming.
In this case the bottom of the cup will be dry looking.
Queen cups containing eggs or larvae that have also been supplied, or primed, with brood food (royal jelly) are treated as a sign of swarming at which point they are referred to as queen cells.
In this case the bottom of the cup is wet looking or there is a more obvious pool of brood food.
If no action is taken at this stage, the queen could depart with a swarm within a week remembering that the first swarm leaves when the first queen cell is sealed.
Removing or destroying all of the queen cells in the hive will delay the process but of course the bees will normally just continue producing more.
The life cycle of the queen dictates how often the colony should be checked for signs of swarming if we are to try to control it.
For example, let's say a colony has just been inspected and no primed cells were found but as soon as our back is turned the colony starts the process with a newly laid egg.
This first queen cell will be sealed (and the swarm depart) in 8 days so it will have to be checked again before then.
Unusually, it is possible that the process is started with a larva that is already up to day 6 of its life.
In this case the first queen cell will be sealed (and the swarm depart) in as few as just 2 days after the inspection.
To guarantee that a swarm is not lost, this would mean inspecting the colony every two days which is madness and not practical for the sake of the bees and the keeper so once a week is an acceptable compromise though with the very small inherent risk of losing a swarm.