We had a call just after lunch, from one of our out apiaries which is on some secure government land, to say that our bees were swarming. The bees have been there since the end of July 2014 so the workforce had never experience a swarm before. We were told that the swarm flew straight out of the hive and initially settled high in a tree and then moved lower down. When we got there we could not find a swarm - just a few bees flying near a tree. We then inspected all three colonies on site. We found the queen, with no play cups or swarm cells in two of the colonies. In the third colony, which was only on three frames of brood, we could not find the queen, but that is not unusual for that particular queen. There were lots of eggs, brood in all stages and lots of bees in the brood box and super. We went through that brood box four times shaking off the bees but there is absolutely no sign of swarm cells of any kind or even play cups. We even went through the super. If they have swarmed, and I am not sure that they have, why have they done so as they had plenty of room, some shade from the sun and no queen cells at all? Can anyone proffer an explanation?