I have 4 hives. All 4 of them have a robbing issue.

Will reducing entrances to less than 1" be sufficient to stop robbing on strong hives? This sucks because there aren't that money warm days left and I've only saw one of my four hives bringing pollen in, it seems they are too busy trying to defend to worry about foraging.

My neighbor's hives, which are about 100' away from mine were robbed out so badly that only 1 of his 3 has survived so far this year. I'm wondering if his final hive has been robbed out so badly that it is now going after mine. Or if there are feral hives around that robbed his and are now going after mine.