what would kill 8 chickens in 1 day????

[cmom]

If you have a game/trail camera, I would put it up. Most likely the predator will be back and then you will know for sure what you are dealing with. I would also suggest coyote. I have several game cameras up on my property and most nights when the predators roam here. Mostly I see coyotes on camera. I rarely see them during the day. I do get fox, coons, possums among some others. Good luck...
There are actually two coyotes in this picture.

 

[Eggsoteric]

My money is on a fox. Fox will absolutely hunt during the day and if they're not caught in the act and stopped in their tracks they can decimate an entire flock. Fox will carry off and cache what they don't eat.