Let's get into our sleeping bags.

(distant voice giggling)

Did you giggle?

I didn't giggle.

You?

Uh-uh.

It wasn't me.

Maybe it was a frog.

Do frogs giggle?

I don't know.

(voice giggling)

Okay, that wasn't a frog!

VOICE: This treehouse is mine!

(voice echoes)

(kids scream)

(thunderclap)

BUSTER: I'm outta here!

(screaming)

Watch "Arthur," weekdays on your PBS Kids station,

or any time on the PBS Kids video app.