Brian's hive has swarmed 4 times this spring. I have been trying to get into mine for a few weeks to look for swarm cells. I checked the weaker hive first and everything looked good. It's growing nicely this spring. There was only a couple of queen cups on the frames that looked like they have been there for a while. When I opened the strong hive I found quite a few swarm cells.
We'll just have to keep an eye out for swarms and try to catch them.