how to stop bee robbing
Whatever the source of robbing, whether it is a colony, a feeder or a pile of supers you will need to remove it quickly, but replace it with a small amount of honey or syrup. A spoonful or two on a plate or saucer will be enough. When the robbing bees have cleared it up they will calm down. If robbing has only just started and the colony being robbed is strong in bees and queenright, then close the entrances of all colonies up to one bee space. You can put some small branches with leaves on in front of the hive to confuse the robbers.