Hi! My name is Nik. I live in Virginia, Hampton Roads. We recently bought a house, while my children were playing outside they found a turtle. They guilted me into keeping it because at the time is was 70 degrees outside but was suppose to drop to freezing that night. I thought it was a box turtle until I went to petsmart and saw a Russian tortoise, and had an aha moment! I have rocks in his tank and noticed he was munching on a couple. I know that some animals do this to aid in digestion. Is this ok?