Part 2/Step 3: Build the Button

Now comes the trickiest part: extending the delicate button switch on the circuit board so that you can trigger it by pressing the top of the rat's back. To accomplish this feat, you'll be gluing a pencil inside the rat, positioned so that pressing on the rat's back triggers the mouse-button switch below.

Use your X-Acto to cut a nickel-size hole in the rat's back directly above the circuit board's button switch. (You'll reattach this piece as the button, so cut carefully, and don't lose the piece.) Now grab a pencil, poke the eraser end into the button hole you just cut, and click the switch a few times to get a feel for it. Now rest the pencil on the switch, and-making sure the switch is not pressed - mark the pencil at the point where it comes out the rat's back. Cut the pencil to that length.

If this part's too tricky, you can cut a smaller hole and just let the pencil stick up through it.