This morning when my son let out the chickens, he found one dead. When I went up to investigate, I saw a headless body, with one side of the organs exposed. There was no blood in the coop, and it didn't look like the organs were ate on. One of my girls is limping and missing feathers on her back, but I don't know if I'm missing any other birds since they are already out in the yard. Last year we had a fox get in and kill 4 and took one, so we tightened security after that. Any idea what could have done this? I'm thinking a raccoon, but I'm not sure how it got in.