I have a 5 foot high fence around the entire back yard to keep the deer out. Deer are capable of jumping a 5 foot fence, but they never have here. I suppose there's enough other stuff for them to eat here in town, so they don't have the feeding pressure to jump the fence. If I leave the gate open overnight, the deer will wander into the back yard and sample the garden. They seem to really like tomato plants for some reason.