I have three hives in my back yard that I installed from swarms last year. Last year they were very calm, but as of a week ago have turned nasty! So much so that we can’t even go into the backyard without being attacked by some guards. My first thoughts were queenless hive or robbing but neither are the case. I’ve inspected the hives for queens and installed reducers to mitigate robbing. All the hives are full of bees and brood with the same marked queens from last year. There is some honey in all the hives but not a lot and nectar is being brought in. The flow is just starting here in mid Ohio. I can’t really tell if it’s one hive or all of them. I thought about closing them up one at a time to see if I can isolate a particular hive. Any thoughts on what could turn a hive nasty right as the flow is getting started? I have other hives in an apiary just down the road and they are still baby dolls.