My Ruby recently started burrowing under her paper towel which I wasn't too happy with so I tried weighing it down as much as possible with other decor items but in general once they know they can get somewhere (and somewhere which is off limits ) they tend to always try and return
Made a border from spare mat/ grass and blue tactd it all around the perimeter of the viv then placed the grass mat on top. Has worked great, so far (touch wood).Have just put in two logs and will be getting some more plants soon for additional hiding places.