They are deadly on coyotes, but you've got to make sure your snare is set up over a coyote trail instead of a rabbit/deer/hog/etc. trail. Normally the coyote has his own beaten path. When you find it, then you need to place a little grass or broomweed or something along both sides so he won't see the snare and will naturally want to stick his head right through where the loop is. And it will damage the area around the neck a little because the coyote will flop and fight it until he wears out.