Did you find a hole where the Critters got in?
I lost all my pen pheasants a couple weeks ago had about 15, also had a few laying hens in the pen [chickens]. I have a good setup, so I thought. I feed/water and check the birds every few days. I get out there and one chicken alive. Couldn't figure out what or how the critter got in. All birds just eaten on a little bit. Mostly the head and insides.
I take the last chicken, put it into a live trap, closed.
Two leg hole traps wired to a cement block set on the outside the livetrap with the poor old chicken in it. [properly feed and watered]
This is all inside my enclosure.
Next morning I have a 40 pound male raccoon in a leg hold. He sees me and tries to climb a post. [5X6]
I found the entry spot. Chicken wire attached the the header had lost a couple staples, the coon would go through, the te wire snap back into place, very hard to see and 12 feet off the ground.
OK, more to the story, the dead birds left in the pen had most all been eaten on again, quite a lot.
. Set the trap again, next morning a large female [nursing] caught. Still more eaten on the dead birds. Next morning another large nursing female.
That was it, got em all. Fixed the hole and released to poor old chicken.
She must have had quite an experience.