If the second swarm had a queen and she was laying eggs, pharmones were stronger, it is a possibility that the first swarm did move out and join up. You see that with packaged bees when several are put into hives in the same area. The queen with the strongest pharmones ends up with all the straglers and some of the workers from other hives. I had 1 out of 10 packages do me that way this year. Good thing was that it didn't hurt the hive too much and after she got to laying they went wild.
Down to three hives
:s So the two nucs I bought a few weeks ago are doing great building comb and pushing up into their second deeps. My swarms I caught are now swarm -single. The first swarm moved out and on to better things. I think I made the mistake of seeing robbing and assuming the bees were working but in fact the stronger swarm was taking everything from its much weaker nieghbor. I looked in today and emptyness. They did draw out some partial comb on one frame and I found a single swarm cell that was on some existing comb i put in there to get them started. I put all the old drawn frame in with the other swarm/hive to help build them up quicker. These guys seem to be happy and look like they will be around awhile. Is it possible the weaker swarm merged with its stronger neighbor during the robbing process? Both swarms were caught in exactly the same place.:scratch:
