Once the bees are building queen cells preventive actions must be taken or they will swarm. In spring check your bees 7 to 10 days for queen cells, the period ensures that if at the last inspection no cells were found then the bees have not reached the point of swarming at the next.
With queen cells present: small invert acorn cells with an egg, larvae or a sealed vertically hanging external cell, the bees are making preparation to swarm. Artificial swarm techniques must be used to control the impulse.
Relocate the original hive within the same apiary site a few metres away. In its place put down a floorboard, an empty box with frames (foundation will do) and a cover and remove a frame. Find the queen and place her into the centre of the box. It is very important to destroy any queen cells that are on the frame with the queen, otherwise the bees will still swarm. All of the field bees will return to the original location, in effect creating a swarm, but with ample space for the queen to lay and little reserves the bees settle in to their ‘new home’. The colony should be inspected regularly and provide additional space as they can build up rapidly.
In the queen less colony, the population declines as the remaining flying bees join the old queen leaving the young nurse bees behind. As swarm is comprised mostly of worker bees; the emerging queen will kill her siblings and with so few flying bees is unlikely to swarm. At the end of the swarming season, the two colonies can be united together, placing the wanted queen on top of the newspaper. The artificial swarm technique is not 100% successful. Further swarming preparations may take place from both colonies.