Cool! I like what you're doing.
And if
none of the hives catches a swarm? Then we assume that swarming behavior doesn't really happen?
Actually, though, I wonder if the house the swarm traps are sitting on would be the control.
I've got my swarm trap in a pittosporum shrub that has been groomed to resemble a tree. The opening is at eye level. I'm worried that while it is convenient for me, it is too low for the bees.
I didn't want to put it too close to my house, because I didn't want to encourage the bees to look for an opening in my soffit.