I was asked to help a fellow bee keeper with a swarm.
When I arrived there was two separate clusters in his neighbours garden. One was 20ft up in a tree and the other was on the side of the climbing frame. We decided to have quick look inside his hives first to see which of them had swarmed, during which time the cluster in the tree combined with the other cluster thankfully as this made collecting them so much easier as I only had one nuc. Once I'd collect over 85-90% of the swarm I left them alone and returned again after 19:30 hrs.
As soon as I approached the nuc I could clearly hear two different pitches of piping. I think each of the original clusters had its own queen. My guess is one is the parent queen the other is one of her daughter queens (princess). At some point they will fight to the death and more often than not the younger and more nimble queen will survive. Over the next few weeks she will need to fly out and mate and then will hopefully start laying before the end of the season when the weather turns cold and the colony start to cluster to keep warm for Winter.