OH I feel for you. something dug under our cement patio step last year and then when i pushed the dirt back and put two small ceramic statues on top, what ever it was also dug under the cement front porch step. my husband said not to fret over it. Well i wanted to know what was trying to live under our house and if it could get in by digging under the steps. I never did know what it was but it hasn't been back.
good luck on getting rid of them. call a skunk whisperer!!!