One of my favorite beginners book is called "The Digging-est Dog". I used to read that book along with "Are You My Mother?" over and over when I was a very little girl.
I call Abby Gail my Digging-est cat due to the fact she frequently digs outside. Dan recently captured Abby Gail doing this very thing. She would stop in her tracks, sniff around and then start digging uncovering gopher holes or tunnels.