The instruction that come with the fence say to only have one invisible gate where the dog can leave the permitted area. And he can only leave through that one spot when you have him on a leash. Our dogs only have one spot, they won't go through unless they are riding on our Ranger, or I grab their neck like a collar and give them a nudge.

Some dogs might learn that they have a fence when the collar is on, and not when it's off. But our dogs have not learned that yet. The Lab goes crazy when you take his collar off, because then he knows you are going to take him walking.