... the hive is empty with really no apparant reason apart from a very small area of one frame looking as if a mouse might have chewed it. There was very little rubbish on the floor, and no immediate evidence of dead bees....But huge amounts of sealed stores. ...
I have experienced similar this year. Two strong colonies going into Winter. No sign of activity in early Feb but I thought it unwise to look. A week ago there were a lot of bees coming and going, so great excitement but looking closer I saw no pollen coming in, some fighting on the landing board, then my young companion said "Is that the Queen there?" as a huge bumble be went straight in the entrance so I knew something was wrong and that I might just be seeing some robbing by other colonies.
Late in the day when flying had stopped I opened the hives to find not a single living bee. some dead bees and some debris on the floor, the comb missing in a small area in the centre of the brood nest but the rest of the comb pretty much intact. I removed a large quantity of stores.
They didn't starve, that's for sure, it didn't look like the mess a mouse makes, it was too late for pesticide issues, no brood so no brood disease... I am thinking it must be mite and virus related. These were colonies in Warre hives that had been neither treated nor fed.
I have found the experience quite upsetting. How messed up is beekeeping if you can't even keep them alive without intrusive management and treatments?