A few weeks ago my mom had a groundhog burrowing under the deck. I had covered it's access hole with dirt but it quickly made another hole. Sprinkled an entire bottle of cayenne pepper in and around the hole. No more groundhog.
But I don't think they dig out in the open so much so that's prob not the issue you have.
2012 Toyota Camry 68k-PUP 5w20,OEM filter, RT43s.
2005 Toyota Matrix 122k miles - MC 5w30 syn-blend, Omnicraft oil filter. Nokian eNTYRES.