Another potential problem is that the bees might find a cavity in a wall in which to make their home. Wall removals can be very difficult and expensive. Since the arrival of a specific Honey bee mite called Varroa in the UK the number of 'wild' honey bee colonies has dropped sharply. Honey bees are valued insects, not just for the honey they produce, but also for the pollination duties they provide. Swarms are collected in differing ways depending on their location, but in general the Beekeeper will do the following.
Some beekeepers even use a kind of vacuum cleaner to hoover the swarm up.
This doesn't harm them and is very quick. On arrival show the beekeeper where the swarm is located. Providing it is safe to access the swarm he may put on his beekeeping clothes - overalls with a black gauze hood and leather gloves. This is simply because he will have to disturb the swarm inorder to move them. He might spray the swarm with a weak sugar solution just to 'calm them down'.