I have had a white tailed bumble bee nest in my compost maker (dalek type) since early summer, I have nurtured them through the summer making sure they have had some sugary water on hand and it has been quite fascinating watching them. Suddenly all activity has ceased and I would like to know if the bees have all hatched in the nest and flown or do they stay in the nest through the winter, I would hate to empty the compost bin if bees were still in it.
Bit early for them to have died off which is what happens in autumn.
Leave them alone if you can- until early mid winter invest in another bin perhaps which is good for the composting process....