When I set traps for coyotes, I pack the dirt outside the jaws with a hammer and nothing moves when I’m done. Inside the jaws and under the pan he can use fiberfill, or a product called an under all, or a pan cover. Most of the time I use a heavy screen that goes over the pan but under the jaws. Same with fox.

I ended up making this and seems to work… might only last a season but it should help my son..