Just google rabbit distress sounds,listen and duplicate.Fox can be tough to call in my area because of the amount of coyotes around.I generally would use more high pitch squeaky sounds.Last one I called in was a beautifull male that I called at 10:00 pm using a wooden squeak call that I would blow with staccato.Learn the lip squeak.I make it by wrapping my hand over my mouth and sucking into my middle finger joint.Seems louder this way then on the back of the hand.Some years there is a lot of natural food and makes it tough.If I called in a lot of owls to my stand instead of them just hooting at me I fiqured it was a good calling year and it generally was.The rabbit distress will call in anything and my favorite was a FAULKS brand adjustable but I have predator calls galore and they all work.Some just freeze up easier.Like mj says just make a variety of sounds of a small animal (or bird) being ripped apart.One year I made 40 sets at about an hour a set in lowlight till one night till 2am and temps to 15 below and never called in anything!Another year I called in numerous coyotes,red,and grey fox.Go fiqure.