A digging box(cardboard box filled with something like crumpled newspaper) will sometimes work. If it doesn't, if your rabbit is digging the carpet or something like that, all you can do is block access with ceramic tiles, wire panels, or maybe putting a cardboard box there to dig in instead. If it's the litter box your rabbit is digging in, I made a soft pet screen to cover my rabbits litter to prevent digging, and it's also topped with grass hay.