I had a couple of snakes attempt to get into my pens and probably into the coops. I do have electric wires around my coops and pens. When the snakes tried to go through the fence and touched the electric wires they were electrocuted. I have my fence grounded so anything that touches the hot wires and the fence will know it. Only once did a snake actually get into a coop. It didn't get into a nest box and it was a rather small snake.