March 2026

Swarming Prevention and Swarm Control by Alan Riach

We are approaching swarming time and so this month we have devoted the Newsletter to swarm prevention and control.
Prevention – The Management actions which discourage the bees from thinking of swarming
Control – The Actions to be taken once the Prevention actions have failed and the bees have decided to swarm.

Prevention:

• Ensure that the hive does not become overcrowded during the late spring build-up. Ensure that sufficient supers are put on, especially during strong flows. The bees need empty cells to dry the nectar into honey as well as space to store it.

•  Young queens are less likely to swarm due to their strong production of queen pheromone. Keep young queens.

• The inclination to swarm is genetic, so don’t breed from “eager swarmers”.

Control:
There are 4 main methods of swarm control: Pagden, Snelgrove, Demaree and the Nucleus method. Once you have decided on a method, practice it and stick with it. The following table outlines the Pros and Cons of these 4 methods. For details of how to carry out these methods, see “Swarm Control - The Four Main Methods” in the download section of the EMBA website.

The notes below summarise the four methods with the pros and cons of each.

Pagden Method: Involves creating an artificial swarm

Pagden Pros:
Maintains a strong nectar-gathering colony and a queen continuing to lay and produce foragers (this is the Artificial swarm)

Good strategy for going to the Heather- the new queen and her colony can be united with the original artificial swarm colony once the old queen is removed to produce a super strong Heather colony.

Pretty well guarantees a good quality new queen in the relocated “mother” colony. That colony, now much weakened (& therefore very unlikely to swarm) by foragers returning to the artificial swarm, can be left on its own until a new queen emerges & is mated. If the original colony had lots of brood, it may need supering once the new queen starts laying.

Pagden Cons:
Needs extra equipment -floor, brood box, crown board and roof
Not always foolproof. If the swarming process is well advanced (within a day or two of leaving) they may still swarm. This can be prevented by putting a queen excluder under the brood box of the artificial swarm for a week or so until they (hopefully) settle down.

Snelgrove method:
A vertical version of the Pagden

Snelgrove Pros:
Uses less equipment to begin with - Broodbox and Snelgrove board. However, once a new queen has emerged and is mated, she will have to be relocated to a new hive, so a new floor, crownboard and roof are required eventually. Similar to other advantages, such as the Pagden, it maintains the foraging power of the colony (the artificial swarm) and guarantees to produce a good-quality new queen in the relocated mother colony.
By manipulating the Snelgrove board, multiple entrances can build up the population of the artificial swarm.

Snelgrove Cons:
The heavy original brood box placed on the top of the box stack above the Snelgrove board has to be lifted off every time an inspection is carried out of the lower queenright broodbox, or if supers have to be removed, so not so good in Canola areas where the supers must be removed promptly.

Needs a special Snelgrove board with multiple upper and lower closable entrances

Demaree method:
A vertical system like the Snelgrove, but instead of ending up with a “new queen” colony, you end up with an artificial swarm containing the old queen and an upper broodbox containing a lot of honey. The upper box could, of course, be used to produce a “ new queen” colony.

Demaree Pros:
Suitable system if it is not intended to produce a new queen. It only requires a new broodbox and an extra queen excluder.

Can be modified to produce a new queen in the upper box by using an extra bee-proof crown board with an upper entrance.

Demaree Cons:
Difficulty in allowing drones to escape from the upper broodbox. Needs a queen excluder below this box to prevent desperate drones from going down into the supers below and defecating in the honey.

Ends up with a lot of honey in the upper broodbox, which may be difficult to extract using normal extractors.

The heavy upper box must be removed every time the hive is inspected or supers are removed.

The Nuc method:
Frustratingly, this is, theoretically, the surest method of preventing a swarm from issuing, but if carried out incorrectly, it guarantees a swarm will issue

Nuc method Pros:
If carried out correctly, it will guarantee that a swarm will not issue. A prime swarm cell is chosen and its position marked with a drawing pin placed on the top bar of the frame containing it. Check 7 days later and remove ALL new queen cells.

Nuc method Cons:
If a second scrubby little queen cell is missed (typically hiding in a lower corner of a frame), then you have guaranteed that when the prime virgin emerges, she will be sent off with a prime swarm, as this is still a strong colony. You are left with a colony headed by a scrubby little queen.

Needs a Nuc box to contain the old queen, two frames of brood with young bees and some food.

Breaks the brood production in the original colony & will lead to a reduction in foraging power.

NOTES
Clipping Queens:
Clipped queens fail to fly with a swarm and are usually lost in the grass. The swarm will then return to the hive. It thus buys time, as the next opportunity for a swarm to issue is when the first virgin emerges.

Panic actions:
If you find lots of sealed (or unsealed) queen cells during an inspection, don’t panic and knock them all down, because if the queen has departed, you will now have prevented the bees from producing a new queen.

Swarms don’t usually leave until the first queen cell(s) are sealed, but there are exceptions. Look carefully for the queen (it is important that you mark your queens).

Finding queens:
If you can’t find the queen, remove two frames (put them in a Nuc box if there is brood on them), checking them thoroughly for the queen
Set up the remaining 8 frames in 4 separated pairs and leave for a few minutes. Remove a pair and open them like the leaves of a book. The queen will usually be in the dark space between one of the dual frames.

Have they swarmed??
Signs of a colony having swarmed – Sealed queen cells. Depleted population, especially in the supers. No queen, no eggs.