As the nectar flows taper off at this time of year robbing sets in. If you only have one hive and you know that there are no others nearby then you don’t need to worry about robbing – but the rest of us do. Robbing is especially a problem when you have strong hives near small, weak or queenless hives – such as splits or mating nucs. Especially if you are feeding those weaker hives. There are lots of ways to manage robbing, but in my opinion, except for robber screens they all just nibble around the edges of the problem. Robber screens work when nothing else will. Even so, robber screens work much better if deployed before robbing sets in, so don’t wait. BTW, if you want to you can leave robber screens on all year long – they won’t hinder a strong hive from making a honey crop, and they make excellent mouse guards in winter.