My RF sometime would dig up & eat dirt "natural soil not pot planting soil" & roots of grass & plants in outdoor grass fields or grass & plants I have planted & placed in it's enclosure, I've also seen her nibbled on stones & tree barks too. This is natural for many other animals, is it to obtain some kind of minerals they lack in their diets or is it to help them digest or as medication? Or is it they look for something toxic to flush out their system?