I picked up two nucs on Sunday one of them was just packed full of bee's the other a little light on bee's the beekeeper inspected every nuc he was selling and checked for queens and this is when he noticed the difference in bee population of the two nucs . He suggested letting them set 3 days in my bee yard and let them get used to there surroundings then swap location and let some foragers drift into the light hive to balance the hive population and I thinking Wes. would be good. Well this brings up something I have been seeing lately and I hope its not robbing . I'll go up to the yard and now on two occasions one hive out of the four will be real busy with bee's hovering outside the hive waiting to get in and this last time it was the one nuc that was lite on bee's , the other day it was the queenright hive of a split I had done about two weeks ago that was also light on bee's from the split and loosing foragers .Is it robbing and what should I look for to determine if it is robbing .