|Overcrowded hive is a swarm waiting to happen. Photo by Todd King|
Got through all the hives looking for uncapped swarm cells and remove them.
In the photo there is one hive that is over crowded and ready to swarm. Move this hive to where the weak hive is and the weak hive to the position where the strong hive is. Move the entire hive.
What happens is the field bees fly out to forage, when they return, they come back to the hive where they think they were. Now the strong hive gets weaker and the weak hive gets much stronger. The strong hive still needs to have the over crowding issues resolved but, this will keep a swarm from happening.