Hello BYC! Just yesterday afternoon we bought 3 chickens, GLWs, and we had them in a large dog cage as I know you can't just add them to your flock. Their cage is inside the pin with our other 6 chickens, 3 BOs and 3 BRs. They are all, including the 3 new ones, about 2 years old. When we got to the place in which we bought them, none of them had their tail feathers, at all and some of the feathers on their back were gone as well, I'm surprised cannibalism hadn't occurred with the shape they were in. (They had mentioned their leghorns were beating of them) We didn't know this in advance I felt really bad for them. Our current chickens were watching and acknowledging them, didn't seem it was going to be a problem. So this morning I brought snacks out to them all plus their water and food. It seemed like it wasn't going to be bad up until we let them out to see what would happen. It all went well at first, the BOs were eating snacks with them side by side and the BRs were too but they had more distance than the BOs. We decided to go in and when we looked out our back window, one of the 2 smaller BRs were biting (biting more than pecking) and bumping chests with one of the GLWs. We ran out there to create attention to try to get them to stop, they stopped for a bit but stared at each other. They started back up again so I snatched the GLW up and put her in the cage. When the others were around, my father had noticed one of the BOs pecked at one of the other GLWs, not a fight but just a peck, so we snatched the other 2 up and put them back in the cage. These GLWs aren't very big, they are smaller than our smallest 2 BRs, and really almost half the size of the biggest BR and the 3 BOs. Has anyone had anything like this happen to them with chickens of the same age? Is it too late to add new chickens to your flock or does it take more time before we let them out? I thought they were good but I now see that they aren't. I don't want our current chickens to think it's ok to take tail feathers off of each other like the new ones are used to. Would our chickens seeing that set an example of how they should treat each other? If anyone has had an experience like this and could it, it would be greatly appreciated. Any advice would be helpful, even if it's telling me that mixing them won't work at all. Thanks a lot for taking the time to read this!