Yep groundhogs suck. None under my deck, but used to have a cavern under my shed. Haven't seen any activity for a couple years since I filled it in when i repaired the floor. Need to look under their and check just in case so I catch the little bastages early if they try to move in again.
Helped a neighbor set a trap yesterday. Giant mound of dirt and hole in her garden where the flowers were. Most are gone including most of the roses! She's pissed!