We had one of our hens sitting on 12 eggs. Two hatched fine and the third one hatch a day later. At that point, the mom had already left the nest so we rescued the chick and brought in under a heat lamp, dried it off and about 12 hours later when it was up and running around we tried to introduce it back to the mom. It didn't go well at first but eventually she seemed to take to it. We left the chick outside last night with the other two chicks and the mom who are in a separate area and when I went out to feed them this morning everyone was fine. About an hour later I went back out to check on them and the introduced chick had a bloody head from being pecked. I've since brought the chick back in but I'm wondering what I did wrong. Any thoughts, suggestions? Anything?