So, accepting that you are going to have some hives swarm, the other part of the equation is putting up swarm traps in hopes of catching them when they do!
Gosh I wish my bees would learn this! My queens seem to go wherever the heck they want. On more than one occasion I've put wet supers back on the hive ABOVE the inner cover for them to clean up, only to go back a couple days later to find the queen laying in them. The biggest lesson I've learned since beginning to keep bees is that my bees don't read the books on how they're supposed to beehave!