Not poop, but scat? lol, when I first moved to the "rural country" I called it "poop" and boy did I get some puzzled looks followed by "oh you mean scat?!?".
I had the joy of watching a fox teach her cubs how to catch a mole, and the kits scamper after the mom, after stopping to do some ruff and tumble play, for a few years. They are very much a cross between a cat and a dog in how they interact and play. I also watched a PBS documentary on fox and they said they can become tame like dogs in just two generations. I've also seen where someone has nursed a kit back to health and keep as a loving pet.
Unlike Raccoons who will just "neck" all your chickens for there blood and leave the carcasses, (I've had it happen), a fox will only take what it eats, which is mostly rodents and an occasional fowl or bird. If you look at the scat you will probably see some remnants which will also help identify it. Cyote's leave a much bigger package then fox, but can also be identified by it's contents vs that of a dog, which won't have any bits of fur or grass. You don't have to get to close for this examination but just a more observant look should let you know.
I'll become alarmed when it's human, then it is called "****" and I'll be sure to post.
