I think I know what happened but just thought I would throw it out here to confirm. I made about 6 nucs, I added 3 frames of emerging brood/ honey frames to each nuc. These are in the same yard. Also added mated queens from queen breeder(Ebert Queens, very good queens). I did this the last week of July 24-28. As of Aug 2 I had eggs and some mature larvae from new queens, also seemed to have good population in all 6 nucs. One of my Nucs that seemed to be one of the strongest as of today only had about a baseball size cluster inside and the queen was still there. The comb was in decent shape and some capped honey was on a couple of the four frames. Now that I'm typing this out I may have figured it out and it isn't what I thought. Original cause was drift back to original hive, this doesn't hold of ton of water because I did not have this issue with the other five. But now that I remember I made up the nucs and the queens were DOA because of a bad mailman left the five queens in mailbox on 102 degree day. (it said not to on the box in a couple of places.) the queen guy mailed more out very quickly but I remember now cutting out queen cells when I was install new queens. I bet one of them hatched and they swarmed on me. It was a small population of bees but I bet that was it. Any thoughts or any other ideas let me know.
(PS I have added another frame of emerging brood to the nuc with a little honey on it.)