Kinda got a mystery going on,, something is killing chickens… bites the heads off and leaves them laying dead in the corner of the coop.
My first thought was a weasel or mink…which are notorious and this is signature sign.
I take a dead piece of chicken and wire it inside a cage trap,,, and throw the bloody guts in for good measure (a small one for small critters like an 18 inch one). the next day,,, the trap is found tossed around and obviously fired….. I automatically assume raccoon.
We set a larger live trap… wire another piece of dead chicken…. And then I go around the coop to make sure he can’t get in….. the door is solid,,, no holes in the walls, corners or ceiling,,,, the only opening there is is the wire over the windows that are like 2x2 mesh,I know a raccoon can squeeze into some really tight spaces… but that’s way too small. I’m baffled at the moment,,, I don’t know what would be big enough to toss a cage trap around,,,yet small enough to fit through a 2x2 mesh.
The only other option I can think of, is to keep the dead chicken in the corner and put a bunch of footholds in front of it,,,, I just wouldn’t know how to keep the other chickens from accidentally getting into them.
Any ideas??

A trail camera would probably solve the mystery.

Is it a coon reaching through and tearing their heads off in the corner? Not going in at all, but doing it from the outside? Maybe why the bodies are left?

I'd set the perimeter like a mine field if it was my chickens.

Sounds like alittle weasel.

yes

My initial thought was a weasel,,, but I don’t see it tossing a cage trap around

Whatever it is, is getting inside the house,,,, the dead chicken is in the opposite corner from where the window is
I set the perimeter up with dogproofs and they were not touched.

Best wire for any window openings for a chicken house is 1/2" x 1" cage wire. Far tougher than the 1/2" hardware cloth a lot like to use, but that will keep out just about everything but wasps and other flying bugs. No weasels, no rats (coming thru the wire) and no reach ins.

Assume you set the tripped cage outside the house and the kills were inside. You may have both weasel inside and coon outside. A least weasel can easily slip thru 1" x 2" wire, and have seen videos that normal weasels can too. Videos of them doing it. And biting heads off several birds is signature move. Also look for claw marks on back, under the wings.

Had an unusual incident back in the summer. Had coons coming around, so set in a hav-a-heart cage, then found it tripped and empty and 30 feet from where it started. It was not staked down. Bait was marshmallows. Either coon got in, got caught and pitched a fit until he forced his way out past the door........or tripped the door, then rolled the cage around the yard until he got the marshmallows out he was after. Replaced hav-a-heart with Wickencamp and a few possums later, caught a big boar. But moral to the story is either wedge cage or stake it down so it can't roll. And even more so if cage has a gravity door that will open if cage is rolled upside down. Catching them the first time is easy. Catching a coon second time......not so much. Possums are slow learners.

Had similar deal. Long story short. When closed up the pen a possum was caught inside some how. Try a DP inside the pen but be prepared to patch the pen as they will destroy anything it can reach.

Possums will just chew the heads off, but hard to believe one could move a live trap...

DPs will catch coon, possum, skunk, and cats. It must be something else. Camera would work, except with chickens in there, they would be setting it off.

I had rats coming in from underneath , Took a minute to realize that one.
Head and neck trauma to my birds.
Best of luck
Yes stake the live trap . first thing they do is try to crawl all over it and reach through the cage walls , I think.

Two different types of evidence may be two different suspects.