I have a Boarder Terrier pup who will pick anything up and chew it from stones wood and leaves. How can I stop him trying to eat everything he shouldn't. It's mainly out on the garden even if I'm next to him when he crunches something he manages to run away. I don't follow him as I don't want it to turn into a game. I've thought of giving him some nice food to get it off him which works but wont he see that as being rewarded for having something he shouldn't have? If I ignore him he carries on.