I use the poly rope wire around my pens and coops. The predators know it's there. My land is mostly open pasture so I don't have trees to deal with but do have nice large covered pens. If your wire or fencing is close enough to trees, some predators can climb the trees to enter the area. I don't free range like I used to but my pens are 200 feet by 60 feet. Don't forget a ground rod. This fence charger is similar to the one I have and this is the poly rope wire. Good luck with whatever you do...