When we built our wooden tortoise table, we knew that our Russian would burrow into the corners and destroy the plastic sheeting that we lined the table with. So we moved some of our flagstone rocks over to the corners and that has seemed to stop him from ripping it with his claws. He loves to burrow into the corners and I was so worried he might suffocate on the lining (since he burrowed through it!). But now, the flat rocks are too heavy for him to burrow under. (And he has two log hides to feel safe in.) One day, we'll switch out the substrate and put down a new sheet of the plastic lining so there won't be any corner holes, but for now these rocks have been working pretty well. I'd like to get a couple more smaller flagstone rocks to put in his enclosure, for him to walk and climb on (as soon as the landscaping place opens!). Anyway, just passing on the tip!