If honey bees they might be able to smoke them out so please get an expert to have a look.
Swarms are awesome BTW - if any of you ever see one just go out and stand there and experience it - magical, honest! I was in the garden with my friend's 3 yr old when we had a swarm and we were both enchanted by it - forget horror movies, swarming bees have better things to do than sting you. If bees sting they die, it's a kamikaze thing - die to protect the hive, but they are on their way to form a new hive so nothing to protect.
This is what someone can do who knows what they are doing - I wouldn't try it but I have seen people handle bees with bare hands.