We have two coops in the same very large run. The main coop houses the "big kids" and our smaller grow out coop has 2-month-old teenagers in it. Last night when my husband locked them up, one of the chicks must have been inside the big coop. We found her dead in the corner. No blood, but an eye was pecked out. She was a mostly white chick, and her body looked normal, but her head was all super dirty and even though I didn't look her over really well before we buried her, I'm sure she died of some sort of head injury or wound. The coop is quite predator proof and no one else was hurt, so it must have been the other chickens, unless something got her before he locked her up. He didn't lock them up until just past dark. But it seems unlikely that a predator would kill a single chick and not harm any of the other 20 in the run. They all get along just beautifully while out in the yard together. She was our favorite of this group. She was the only one who would jump right onto my foot and wait to be picked up when I went into the run. So bummed.