We have recently purchased two horsefield tortoises and was given wood chipping as bedding after finding out more about them we was told that if they injest this it could cause serious health problems so changed to a recomended which we was told was tortoise bedding its called herbi veg and can only be described as dried pellets of grass just wanted to check that this is suitible? Also they love to dig in a built up pile in one corner is this safe or can it suffocate them if it caved in and covers them completly as it does not stick?