It is amazing how many beekeepers don’t know what happens in a colony of bees in the days before and after it swarms. This is one of the basics that should be learnt very early on. If you don’t know what happens, how are you going to prevent it, or deal with the colony once it has swarmed? For some reason many don’t see the life cycle of the queen as being relevant either!

There is a lot written about swarming. I have written this article in steps for convenience.

I believe the colony may be making preparation for a time before the initial signs are shown. It is my view that some of the well publicised “swarm triggers” may not be what the colony has in mind. I believe, based on my observations, swarming could be triggered by several factors. I believe excessive co2, heat and humidity are all would Be causes of swarming. For the vast majority of beekeepers this first stage can be ignored.
An egg is laid in a queen cell. This is probably the first sign a beekeeper will see. For convenience it should be seen as the first to reach all stages, but this may not be the case as I suspect there is some variation in development. Eggs are laid in other queen cells over 6-7 days, giving a staggering in ages.
The colony sends out scouts to look for a suitable nest.
After 3 days the eggs in the queen cells hatch into larvae.
8-9 days after the laying of the first egg the queen cell will be sealed. At this point the swarm will issue from the hive. It can be delayed, perhaps because the cell is sealed too late in the day or because the weather is bad, in which case the delay can be several days. If the delay is too long the colony can abort the process by destroying the queen cells. Once a swarm has issued it is an independant unit.
The swarm will cluster nearby, presumably to collect the queen and the required number of worker bees. It could stay a few minutes, or in some cases build a nest in the open. Most normally stay a few hours.
15-16 days after the laying of the egg the first virgin queen will emerge. One of two things will happen, either she will kill her sisters/half sisters in their cells (this may be with the help of workers), get mated and head the colony, or she may take off with another swarm, called a cast, and leave the next queen to emerge to head the colony.
The above is what normally happens and is what all swarm control methods are designed to interrupt. The understanding of the swarming process is absolutely crucial to understanding what each method is trying to achieve. It is absolutely pointless trying to follow a system in steps A-B-C…. without knowing what the bees are trying to do. That is an easy way to failure.

I have observed many swarms issuing from hives and queens can emerge very early or very late. There seems to be no consistency.

Less than three eggs/larvae in queen cells may be supersedure cells and a sign there is a problem with the queen.

A colony in the right condition will swarm on all kinds of queen cells, even though they did not originally intend to swarm.

In my experience swarms always cluster where at least two ley lines cross. When they select their final nest site they are also where at least two ley lines cross. I know there are many who simply won’t believe this, but that is my experience of several hundred cases, with not one negative.

Some sources suggest it is bees from a clustered swarm that send out scouts – they may do, but I believe the work has already been done and the colony knows where it is going. My thinking is that if you have a pile of boxes with comb in, or an empty hive, there is usually about a week’s activity before a swarm arrives. I’m going on my observation. Again these observations contradict conventional wisdom but this is just what I have come up with based on what I have witnessed.