Almost certainly a fox. The hens were probably cached (or just grabbed and temporarily stashed before the feast) and you should be able to find the location as there will be a lot of nothing but feathers. From this point it is a matter of searching out the most likely area within a couple hundred yards that would serve as a good area for a den (south facing hillside, big hickory/oak snags that have easily dug soil at base). We've had some luck with both snares (along fence lines they like to travel) and leg holds but, we've shot far more than we've trapped.
If it is a fox it will return in a couple of days at about the same time. Have your rifle/shotgun handy. If it sees you and takes off, wait a while, they can't resist coming back for another look.
Good luck to you and your roo!