This morning we noticed something has dug a large hole (20-30cm wide) under our compost heap. I'm not sure if they were digging out of our garden or into it. Based on my research I think it is either a badger sett or fox den based on its size. We live next to a small wooded area (about 100m away from the edge), so I think both badgers and foxes likely live near us. Is there anything I can do to distinguish between these?