DORA: What's the recipe for pee?
WENDELL: Your blood.
DORA: Your kidding? Doesn't it come from the food you eat -- just like poop?
WENDELL: Some of the liquid does come from the food you eat. But unlike poop -- which is dried up food leftovers that travel through your digestive system -- water from food goes into your blood where it is then filtered out by your kidneys to your bladder and then ultimately out your body. Pee and poop never meet up -- except maybe in the toilet!

DORA: Why is pee yellow?
WENDELL: Bile.
DORA: Huh?
WENDELL: Bile. It's a chemical that breaks up fat. It's made by your liver. When you break down bile, some pigments in it make poop brown; another one in bile, urichrome, makes pee yellow. Of course, how dark a yellow or how light and mellow yellow your urine is depends on other things.
DORA: Like what?
WENDELL: Next time you pee check out the color and try to remember how much liquid you've had to drink. The lighter the color, the more liquid there's been to water down the urichrome.

DORA: Where's the water in pee come from?
WENDELL: Burps are the sounds you make when extra gas quickly escapes from your stomach, up through your esophagus and mouth. Farts, on the other hand, are the sounds and smells of extra gas escaping down your large intestine and out through your anus. That gas can travel through your body in just 30 to 45 minutes. Burps travel up and out even faster!

DORA: When does pee smell?
WENDELL: Hardly ever.
DORA: Wendell, have you fallen off your dirt mound? Of course it does!
WENDELL: No, Dora. Unlike poop, the pee inside you is entirely odorless! Now poop smells because of chemicals made by bacteria, those microscopic germs, munching on poop even inside your body.
DORA: Oh-h-h-h-h-h-h great! I just had to ask...!
WENDELL: But, don't worry Dora, there are no bacteria swimming in the pee inside you! The smell you're thinking of happens as the result of chemistry taking place outside your body. When pee has been sitting around -- on a diaper or around a toilet, for example -- the urea in it begins to break down. Know what it makes?
DORA: Nope.
WENDELL: Ammonia and carbon dioxide! What you smell is the ammonia -- the same chemical some people clean with. If there's enough of it, it may even make your eyes burn.
DORA: Why do I always wake up in the morning needing to pee?
WENDELL: Because your body's been real busy! All night long it's been busy filtering out wastes and water from your blood! Now don't you think pee is wonderful?