I know this isn't really a behavioral issue but Beau (3mo) eats our landscaping rocks. Not the big ones, but the little broken pieces. I try to keep him away from them when we walk by but he still manages to reach out and snatch one up. I've swept most of them away but every rainfall brings more. It's not just the landscaping rocks either, he'll eat random rocks in the yard. Any suggestions? I don't want him breaking a tooth or swallowing one.