I've installed hundreds of queens and never had happen what I seen today. I know it is normal for field bees outside the hive to be attracted to queens, especially when you are in a yard of queenless hives. I usually carry a bar of queens as I go from hive to hive installing them and never had them attacking the queens outside the hive. I lost 3 queens today before I realized what was happening. My queens were being stung through the cage(plastic) as I was going from hive to hive installing. I wasn't placing the bar of queens on top of open hives, I was placing them on the ground in the shade. I even found that some of the bees were so agressive to those queens that a few workers were getting their heads through the cage. All queens were checked as soon as they were taken out of the queen box and they were fine. When I was all done I looked at the almost dead queens that were having some kind of seizure and 1 of them had a stinger sticking out of her mouth. All of the hives in this yard were queenless for at least 13 hrs. Has anyone ever had this happen?