Man of Honour
If they are honey bees (check the link below for identification) talk to your local beekeepers society or check here https://www.bbka.org.uk/swarm please don’t kill them unless you have to but be aware that they can do some damage in cavity walls as they create and store honey in the space.
If they are bumble bees they won’t cause any harm so you can leave them till the winter when they’ll leave, then block the hole.
If they are bumble bees they won’t cause any harm so you can leave them till the winter when they’ll leave, then block the hole.