Or raccoon. They will pull them through a fence and pull off the head. They will also get into the coop and pull off the heads. So sorry for your loss. It is very sad. Don't beat yourself up. It happens all the time and it is not reasonable for you to expect to be there watching at all hours of the day and night. It is part of nature. Make sure your others are protected... smaller wire, filling any possible holes, etc. Try to make it a learning experience.
I was very frustrated after a baby I assisted hatch and kept safe and made sure was happy and healthy as at 6 weeks I could only watch a hawk carry it away for dinner. I know it does not feel good!
I was very frustrated after a baby I assisted hatch and kept safe and made sure was happy and healthy as at 6 weeks I could only watch a hawk carry it away for dinner. I know it does not feel good!