Mike, to try and make things even a little bit more clear. It is common for humans who have an apiary to set up swarm traps in the vicinity. When the hive is getting ready to swarm, there are scout bees that (sometimes they swarm and then the scout bees go out in search of a new home) go out and search for an appropriate home. There can be many scout bees that go out and they all can chose a different home, they basically figure it out between themselves which is the most appropriate. If a beekeeper has a home ready for them, and they like this home, that is what they will chose. The first stopping point for a swarm is usually in a reasonable proximity to the original colony. The swarm may move again to another "resting" spot" before they move into a new place. Bees like to move into a home that has already been used by bees, has the queen pheromone scent still present, comb that has been used before and so on, everything that makes for a nice comfy move-in. That is why beekeepers like to "lure" the swarm there, using swarm lure pheromones, like the dead queens that some humans collect. This is a good way to be able to catch the swarms that may have issued from one's apiary. It is a good thing.
And yes, we all need to prevent swarms, there are many ways to prevent swarming and that is one of the biggest bugaboos of the beekeeper, to keep the hives strong, yet not so strong that they have to search for a new home because they are busting out of the box......it is a big job. Have a great, wonderful and awesome day, love our lives we live. Cindi