I had an outside swarm come to my bait hive yesterday at about 11:00 am. This is the 7th swarm to come from the outside to my house this season. The pattern seems to be scouts check out the bait hive. If they like it, it looks like 8 or 10 scouts occupy the hive and "hold" it for the colony. They seem to be occupying the bait hive about a day before the swarm arrives. I wonder if this is what happens when bees come out in a cluster, stay very briefly, and then leave for their permanent location.
I have been using 2 mediums for my bait hive. The top medium has 1 old drawn frame and 9 undrawn. The bottom medium is empty. I have an entrance reducer on with the large opening. I spray 1 shot of swarm commander on the inner cover and one on the landing board. When a swarm arrives, I let it settle in until I see them bringing in pollen. The switch in bait and switch happens when I see the size of the swarm. These lately have been very small, so I am moving them into nucs. Once I see queen laying patterns, I'll start the process of combining several of these small swarms into 1 decent sized colony.