Thanks SarahThey dig and will tunnel! Line the base if you can with chicken wire or similar small mesh. Overlap beyond perimeter. I use builders breeze blocks as a perimeter for height and then finished with decorative bricks that overlap to avoid reach and climb. Use orchid bark substrate to provide a digging area and add low stones and hides for shelter also flower pot bases for food and water wallowing Others may have ideas. What a lovely enclosure it will make. Just make it escape and prey proof and you will have a happy tortoise.