A friend kept bees on my property. I love the little critters, they're very interesting. One day I got to test something I was told about them when they swarmed.
I was weeding, my back was to the hives but I soon became aware of this low hum. It was getting louder. I looked up from my weeding just in time to see a large swarm leaving the hives. What I had been told was if you bang on something metal it confuses the bees. They hear it as thunder, rain is death to bees, and they will coalesce to the closest protected spot they can find so as to protect the queen. It WORKED! They found a somewhat low branch in a pine tree at the edge of the field. I banged again, just to keep 'em there and ran to call my friend to bring a new box. He showed up and started another hive from the swarm.