I found out how it got in, lucky for me it was still stuck in the coop. It couldn't get out,( we had already removed the others immediately this morning ) and I was able to get my revenge for my little ones. I just had to cull the little red, her leg wasn't the only injury. Hardest thing I've ever had to do especially cause she was mine. Even sadder my 75lb pittbull loves the chicks and started howling, he now won't leave the other 2 who are refusing to go back in the coop.