There are different reasons why bees swarm, one of the main reasons in May – July months is as the bee population increases, the hive can become congested and the Queen is running out of space to lay her eggs.
During the summer months, your hive lay look like the one on the left with a single brood box, queen and two supers.
Step 1: Prepare a second brood box, using drawn comb and leave a gap in the middle, approx 2 frames.
Step 2: Remove original brood box and place to one side, add the newly prepared brood box in its place.
Step 3: Find the queen (using a queen catcher or other method) and place her along with a frame of unsealed brood into the gap made in new brood box as this may help encourage her to lay. Careful there are no queen cells on the frame. Close up the gap in the middle and place another frame on the outside (ensure there are no more spaces).
Step 4: Place a queen excluder on top of the new brood box.
Step 5: Place the old brood box on top of the two supers, with a crown board.
Step 6: Check there are no more queen cells in the old brood box.
Important: To avoid swarming, check the top brood box within 5 or 6 days to make sure there are no more queen cells which may need to be removed.
After 25 days, it should be okay to remove the brood box as all eggs will have hatched.
Artificial Swarm Method
The ideal time for this method is when drone cells appear.
Step 1: Remove the roof, crown board, supers (if any) and Queen excluder from original hive.
Step 2: Move original hive floor and brood box about one metre to the left of the original site but at right angles to it, giving it a small entrance to prevent robbing. Ensure there are no Queen cells in this box but eggs to allow the bees to make Queen cells.
Step 3: Put a new floor and brood box on the original site. Put 2 frames of brood, one with the old (marked) Queen on it into the middle of the new brood box and fill the box with frames of foundation or drawn comb, if available, making sure that there are no Queen cells in these frames.
Step 4: If supers have been on an old brood box, fit the queen excluder, the supers, crown board and roof, to the new. If feeding is required, feed with sugar syrup after taking the supers off and reducing the entrance to prevent any robbing.
Step 5: Push the frames together in the old brood box and put 2 frames with foundation to the outside of the box, filling the gap left by removing the 2 frames of brood, one with the Queen. This box contains all the nurse bees which are tending the brood. The bees will soon realise that they have no Queen and start making Queen cells.
Step 6: Feed the old box after 48 hours with sugar syrup. By this time, all the flying foraging bees will have returned to the Queen in the new box on the original site as they are used to this location. This will reduce the chance of robbing from the old box and, depleted of bees, should not think about swarming again that year.
Step 7: The hive entrance should also be reduced as this will help the bees defend the box from robbers. With very few nurse bees and very little brood, the colony in the new box with the Queen usually ceases further swarming attempts.
The old box, having lost all its foraging bees, young bees start foraging for nectar and pollen. As they have never oriented to the original hive position, where the new brood box is situated, they return to the old brood box. Leave this situation for a maximum of 1 week.
Step 8: A maximum of 1 week later (because any Queen cells in the old box will be close to being capped), move this box one metre to the right of the original position, again at right angles to it.
All the young bees that have started foraging from the old box on the other side of the original position cannot find their hive, so drift back to the nearest hive which is the new box in the original position with the old queen. Leave this situation for a maximum of another week.
The original colony is now further depleted in bees. With hardly any foraging bees, it loses its swarming instinct.
Leave only 2 Queen cells in the old box, marking their positions on the brood frames. The old brood box can now be moved to another site within the apiary or elsewhere (the new Queens will not be far from emerging). A new Queen will now emerge to head up the colony, reducing the chances of a cast swarm*.
If there is more than one Queen cell, the Queen that emerges first will kill the other Queens by either stinging them in their Queen cells before they emerge or fighting with them.
Allow 4 weeks from the emergence of a new Queen to mate and start laying (try not to disturb the colony at this time).
* A cast swarm is a 2nd or 3rd swarm with a virgin Queen.