What the HELL is tearing up my garden?

All along the walls in our back garden, something has been digging. This was a month ago:

This was two weeks ago:

It’s much, much worse now. What the hell could it be? It’s not birds, or cats, or our dog. I doubt a fox or badger would come in our wee space – the gate is very low and the space is small and reeks of dog.

Could we have a resident hedgehog? What the hell else could be doing this? Helppppp 🙂