Looking for the title of a children's book w/ rodent protagonists.?

As as child, I remember loving a book that had two animals as protagonists, and I think they may have been moles or some other similar creature. They definitely had an underground dwelling, but I also remember details such as the creatures eating fruit from a cactus. There was additionally some reference to the moon being made of cheese. Can you think of any such book? I would love to find it, but I cannot for the life of me remember what it is! Thanks!