I think he is just digging and knows he is not supposed to. I walked in on him digging his bed and he stopped as soon as he seen me. When I heard him on my bed I got out of the living room recliner and heard him jump off the bed. ... acting all guilty...I hadn't yelled at him yet either time.
I used to pack steel wool around pipes when I was living in a can. I probably didn't need to cause I had 2 great mousers but I did it anyway. Adding steel wool to my shopping list cause mice need to NOT come inside.
There are some endangered creatures that once we learn things (things that once seen cannot be unseen) the "endangered" status makes a ton more sense.

You tried hard to save them.