I have mice!

Well about a week ago we heard some noise in the bathroom walls. I've been watching my every step.
A few days ago I found a hole in the pantry where they or he chewed to get through. I still have not found any droppings (true sign they're around).
Just yesterday my Dad asked if I had heard anymore noises. No noises lately, I said.
Then today I heard some pounding/knocking whatever but it wasn't me and it wasn't Christina. So who do you think it is?
Well I just started thinking, "What the heck are they doing?"
Sounds like they're building something! Then I remembered the show "The Littles". I thought wouldn't it be nice if they looked like this...

and not this...