I must confess that I have never seen robbing on one of my hives to the degree you describe and I think from what has been said two things differentiate severe robbing from orientation:Steve 1972 wrote: ↑12 Aug 2020, 19:08I have lost one Nuc through robbing and since that sad occasion i have not lost anymore..the signs are now obvious to me but hard to spot unless you see it happening a few times over..no fighting and very few dead bees on the floor below the hive....what gives the game away for me is more inward activity than out going..when i say inward activity i mean masses of bees frantically trying to get in but very few flying out with numbers trying to get in quickly growing..the guard bees seem to give up in the end which basically gives the green light for a free meal and bees from several colonies can target one nuc once this starts..it is like a mad frenzy at the entrance unlike orientation flights where the bees mull around the hive flying in circles for 20 minutes or more..
Wasp robbing is easy to solve but bees robbing another Bee colony is hard to stop..that is why i now move any newly made nucs and nucs into brood boxes well away from my strong colonies..
Orientation is usually short-lived and features the bees running around on the hive/landing board, launching off and "hovering" in front of the hive
Robbing is straight in/out no evidence of challenging or guard bee activity
I guess that what this thread underlines is the need to observe the landing board regularly and on different occasions. If you had to choose what was happening from just one look it makes it all the more difficult?