SPEAKER: Thus far, Scratch has pretty much been on autopilot. Let's make this program a little more interactive, such that Scratch will only meow when I pet him, as by moving my mouse cursor over the cat. Let's begin. When green flag clicked, forever, let's do the following. If I detect that the mouse pointer is over the cat, I need to sense that. So let's grab the touching Boolean expression. Change it to mouse pointer. So if while doing this forever, the sprite is touching the mouse pointer, I want to go and meow like a happy cat. Let's give Scratch a moment to catch his breath as usual, upping the default one second to two seconds. Now let's click that green flag. Hmm. Nothing's happening. But that's because nothing's touching the cat yet. So let's move my mouse pointer over him. SCRATCH: [MEOWING]. SPEAKER: Hmm. SCRATCH: [MEOWING]. SPEAKER: Hmm. SCRATCH: [MEOWING]. That's a happy cat.