I put some old honeycomb out to open feed my bees, and reduced the entrances on all my hives. Most of the hives had pretty controlled activity around their reduced entrances, and didn't look like too much robbing was taking place. However, one of my stronger nucs had a pretty serious brawl going on at the landing pad. I could not tell if it was robbing or just a bunch of tee'ed off bees in a traffic jam (I had reduced their entrance to a single bee width).
How do you tell?
How do you tell?