Part of the Gross Science series, here's a book flush with facts on the number-one topic of interest to kids: going number two Overflowing with the science and history of poop (and pee), Poopy Science covers everything kids ever wanted to know (and more ) about their favorite subject. Both expertly researched and hilarious, this book starts with human waste, including: what's in our poop, how our digestive system works, what...