Hint: Digs holes
The answer to this puzzle is:
1. MEERKAT
2. GOPHER
3. GRUB
4. SKUNK
5. MOUSE
6. CHIPMUNK
7. SPIDER
8. TORTOISE
9. DIGGER
10. TOAD
11. PICK
12. SPADE
13. GERBIL
2. GOPHER
3. GRUB
4. SKUNK
5. MOUSE
6. CHIPMUNK
7. SPIDER
8. TORTOISE
9. DIGGER
10. TOAD
11. PICK
12. SPADE
13. GERBIL