lost three hens what could have killed them

I'm so sorry to hear that - it is very sad.

My guess would be a raccoon since they are know to kill whole flocks without eating any just for the sake of killing.

I live in west TN and the list of predators if pretty long.  When did the attack occur (night or day time)?  Were they in coop, house, pen or free ranging.  If they were in the coop can you figure how the pred got in?

Foxes and hawks often leave feathers or nothing and usually take what they want to eat.  Dogs will kill for the fun of it but they usually kill them all unless they are interupted.  Racoons and opossums kill and may eat part of the bird and leave the rest.  I have had a feral cat come back to eat on one that was missing part of it's head and upper body but I don't know for sure if it killed it.  All of these predators have attacked at various times of day for me.  You may can solve the mystery with the trap but I caught so many types of predators that it was totally confusing.

Sorry about your loss and hope you can save your other birds.  Point of lay is an awful time to be loosing them.

I would guess racoon or opposum.  Good luck.

Sounds like a dog to me. Coon, coyotes, fox, bobcats, just about any of the usual suspects would have eaten the birds or at least eaten a large portion of them. Killing them and leaving them laying there is the M.O. of your neighbors pooch.

I hear coons find marshmallows irresistible . And sticky buns. So sorry about your chickens. It really stinks.

Get yourself a 220 connibear type trap and a pair of setting tongs (unless you have gorilla arms).  Use 2 heavy spikes to secure spring loops so opening of trap covers existing point of entry well above ground.  This trap will usually break the neck, if not death will occur rather quickly from strangulation.  You want the jaws to close vertically in relation to the animals entry.

If you use a box trap, coons cannot resist a combination of bacon grease and anise or vanilla oil.  Let it set up and goop it right on the pan.  Wet cat food also works well, as will the carcass of one of your fallen heroes.  Short time in chickens, long time trapping.  Happy hunting. 

Lead poisoning is the surest cure.  #4 or 6 shot at close range is plenty for a coon and will do less damage to your buildings.