I awoke this morning to three dead hens in my run--killed and eaten by my other three hens. The question I have is if I should cull the hens that are left. Here is the situation: The three that were killed were 7 months old and the others are 2 years old. They all had been co-mingling in one large 20'x20' run over the last month with two hen houses to go between. The younger girls had been in an adjoining run the previous months so everyone "got to know" each other before I opened up the gate between the two runs. Everyone had seemed to figure out their place--no pecking was happening and there was some chasing here and there--normal behavior. What was different: Yesterday I had decided to do spring cleaning on the smaller girl's run and didn't get finish and left it closed overnight--keeping everyone in the larger run together without the possibility of going back and forth between the two runs. I am wondering if a turf war broke out overnight and the older girls didn't like being "forced" to share their space. That being said, I have two 3-week-old chicks inside the house that I am now reconsidering intermixing with the older girls now at any time. I feel absolutely terrible about this happening, thinking it was preventible, but at the same time understanding chickens do what chickens do. Do I cull the three in order to try and prevent this happening to my future hens? Any advice would be appreciated!