I was reading and it says that you can put a special openning on the entrance so only the workers can go but this would have to be removed for spring cleaning of the drones. Bye
That is at least 50 year old method. UH, not working.
The best methods to manage with swarming
1) Find a stock which is "slow" to swarm.
2) Do not save the queen which is daughter of swarm.
3) Give space at right time
4) If there are capped queen cells, it swarms. Put hive to new place 2 m apart and put a new hive in the old place with foundations. And put into the new hive queen and that cake on which she is just laying eggs.
Old bees fly to new hive and the rest from colony stay in old hive and keep brood warm. They cannot swarm any more.
The most important thing is that if you not let bees to swarm, queen stops egg laying. So you will not have maximal volume of bees for main blossom.
It important that queen continues egg laying.
When hive is devided, they cannot collect honey. But when honey yield begins, put the old and the new together. So you have there a new queen. Kill the old one or do a nuc.
If you have a stock wich is eager to swarm, nothing can save you from disaster and lack of honey.
Beekeepers have many kind of tricks, but this is the clue in swarming.