Hi I’ve had my bearded dragon for about 5 months, he’s 6 months old and today I noticed he started scratching the bottom of his tank, i have a long green matt that covers the glass bottom of the tank and he just scratches it up until he’s underneath the mat and just remains there. I was wondering if i’d have to buy substrate since I know there are bearded dragons who like to dig. Please someone reply I’d love to get multiple responses if possible