Originally Posted by
AlexG
Bumble bees do not form colonies like honey bees. Honey bee queens will continue laying eggs for a few years, the workers’ and drones’ lifetimes are much shorter, but the colony will establish in one place and stay there for ages with multiple brood cycles.
Bumble bees are all ‘single season’ I think and nests are used for one brood and then abandoned.
I’d recommend contacting the local bee club for advice (beekeepers are always keen to catch a swarm), though a swarm in a chimney cavity is going to be hard work and they may not be interested or able to help. You need to move pretty quickly before they have settled in.
When you have got rid of them get someone to sort out the cracks in the mortar - often swarms will leave pheromones that will attract swarms in subsequent years.
PS - my partner is the beekeeper, but I have spent plenty of time waiting at bee talks and helping out to pick up a little about it.