What's a mouse?

Daredevil was doing a math worksheet where you do the problems, match the answers to letters, to find out a secret word. Then you had to draw a picture of the word.

So he does the adding, matches up the letters, and finds out it's a mouse. "I don't know how to draw a mouse." he says. I tell him "It's like a rat, but smaller."

He says, "It's ok, I'll just trace that one over there." I look to where he's looking and see a fish coloring book on the floor. I wonder what he is going to trace out of the book, when he goes over to the computer and traces....the mouse.