yes I have spoken to a few local beekeepers and they didn't know exactly what had happened , but one had had the same thing happen to a couple of his hives.
One day they were there and then I noticed no noise or movement from the hive , looked and they were gone ... very few dead bees , full brood chamber, and 2 full supers ?
I was going to take the honey and clean everything out when the weather got warmer , but other things got in the way and didn't get round to it . Then the new swarm moved in , cleaned it all out and got stuck in .....they seem well settled in now anyway . They were out the other day when it was warm , off to the loo no doubt !!
Hopefully I will get some honey this year , if these ones stay ?
cheers
Russ