I live on 3 acres with about a quarter acre fenced in outside my back door for the dogs. In 40 years, I have never had a problem. I actually keep an acre totally overgrown with a large deadfall on the front edge. Everything lives back there. . .rabbits, possums, armadillos, racoons, squirrels, deer, mice, rats, chipmunks, snakes of all kinds. I have never had a creature come inside the fence with the exception of a black or king snake. I just pick them up and relocate them if needed. . .don't want the dogs to hurt them.