I used dowsing rods to locate the most inept beekeeper in the district, so ended up placing my bait hives next to my own beehives.
I didn't get a swarm in a bait hive because, being inept and a bee-fiddler, I spotted the swarm leaving and then caught and boxed it PDQ. For a few days prior I had seen lots of interest at a bait-hive just ten metres from the hive, which, in retrospect, I presumed were my own.
But I shall ignore what I have learned from this personal experience and that of
@Curly green finger's because clearly, we are both simplistic theorists who wouldn't know one end of a magic wand from another.