Today was beautiful outside and I hadn't checked the hives in a while so I went out to see if more supers were in order. I had one hive that has been very weak (think I lost the queen) and I had added a frame with some eggs so they could make their own. Anyway, when I went up to the hive I saw some bees clustered on the bottom of the 2x4 stand and I looked and there was about a basketball sized cluster of bees on the underside of the screened bottom board. I looked inside the hive and there was no evidance of a queen but the bees clustered on the underside of the screened bottom board had some freshly drawn comb. Last week or week before, I captured a nice swarm and put them in a nuc box and they absconded. Wonder if these today could have been the ones that absconded. Alternatively, perhaps a queen on her mating flight came back and got confused and went to the underside of the hive and when she got down there a bunch of bees from the hive came down where she was?? I think the absconded swarm taking up residence on the underside of a queenless hive (although there were still many bees in the hive) may be a better guess? The comb on the underside of the screened bottom board was all fresh white comb but I didn't check to see if a queen was in it or not. I took the bottomboard and put it on top of a box with drawn comb and then newspaper and then I put the cluster and empty hive box on top of the other hive boxes. Any other ideas about what could have happened? I've never seen a hive with comb in the open like that before. My hive stand is made of 2x4s nailed on to 4x4 treated corner posts and is about 18" high off the ground but other than that the sides are all open and the new comb and cluster of bees was just hanging there on the bottom of the screen. Something new every day. I'd post some pics if I new how.