Today I swapped out the old tupperware lid we were using to feed our Sulcata on for a flat stone that blends and looks a lot better in his home. As soon as I finished placing the stone my tort came out quickly and began trying to bite or eat the stone. I went and put some food there for him and he couldn't have cared less, he was way too busy with the stone. Is this normal? Is this just a personality trait, or is it common behavior in Sulcatas? Is he trying to tell me something?