For coyote's get the biggest and heaviest drag you can as some yotes will pick up small light one's in their mouth and run with them which leave's you nothing to follow them by.
Some yote's will also run down the middle of a road a distance too so the sharp point's on the ends of the drag will help to make marks in hard packed roads for you to follow. Main thing is when you come upon a empty trap bed don't start trampling all over looking for the animal, just stand still and scan the area first and then begin tracking after you have located sign of which way it went, running all over you may step on drag marks and make the search alot harder than it has to be. Some yotes can go a long way's on a drag, just remember that.
And if bobcats are in the area look up in tree's before going under them, I had to learn that lesson the hard way too, lol.