I have raised several queens this season and made several splits As advised here by iddee and others I wait 30 days before opening a hive after introducing a queen cell. I have had very satisfactory results! I opened some recent splits about 3 weeks ago and had a very good percentage of new laying queens. Just a few days ago, and after giving them plenty of time to be settled in as to my understanding, I went back and marked these new queens as always. Never had a problem until this once. A beautiful new queen about the color of Mr Vans Thelma Lou was next to be marked. I caught her, marked her with the green and waited until the paint was dry. Then back into the hive she went. But Immediately her very own bees attacked her viciously! Balled her and was stinging her! She had three good frames of tight patterned capped brood and even still they attacked their on Queen! I immediately tried rescuing her, placed her in a queen cage, and placed her wedged between frames over night. I checked on her early the next morning. She seemed very weak. I pulled a frame of capped brood and release her there and the bees finished her off. Anyone here ever have a similar experience?