My Dad has lost hives to yellow jackets and had a lot of robbing done by hornets too, if I remember right. Mostly it was the small hives that were lost. He never lost a large, strong colony to invaders because the fight them off if they can.
I have a question (from my skeptical room mates) no one here has asked:
Do your bees and chickens cohabitate well? Should they be separated by a fence?
I had both growing up and I do not recall any problems. The chickens free ranged in the field with the hives which were just out in the open. I know they weren't fenced because I remember going out as a kid when I needed alone time and sitting on top of the hives in the sunshine. My brother, for whatever reason, tends to make bees feel defensive, but they have never bothered me. I have only been stung thrice, and all 3 were yellowjackets- but even so it was not aggression but accidental stings. My Dad actually goes out and pulls frames out in jeans and a t shirt and brushes bees off them with his bare hands to show curious visitors what the frames look like. Animals like us.
I miss bees. Anyone on this thread in my area? Would be nice to have a bee buddy in Southern Oregon.