It depends on the bees.
Working in the countryside, I have got to know a few beekeepers. They'll tell you that some colonies are very laid back, and won't sting unless they're really provoked. Others are grumpy as hell, and will attack en masse anything that comes close to their hive.
They like to know about swarms - bees swarm when they're thinking about moving house. They might set up in a hollow in a tree, in your attic, or even in the boot of your car if they think it'll suit. When a beekeeper gets to hear about a swarm he'll come running. It might be one of his colonies. Once it's in the box, he can introduce it to one of his hives and induce it to stay there. Even if it isn't one of his colonies, he can adopt it anyway!
Although he may regret it if it turns out to be a colony of grumpy bees.
As Winnie the Pooh said, you never can tell with bees...