[Clearly, Sokka is going to have to watch this practically firsthand to see how they work, but that does intrigue him. He crosses one arm across his chest while the other is raised to put a finger on his cheek.]

Huh. I'm sure there's got to be a perfectly good reason how they work then. If only there was a spare one around to tinker with.

[Of course, he is talking about a world where strange magical creatures like Appa are practically commonplace. So whether or not he could ACTUALLY figure them out is another matter altogether.]