And then theres Poo.
This isn't a toilet training book or a book that thinks its funny just to say "Poo". Written by Nicola Davies - a Zooologist - it explains, among other things, how much we can learn about animal from their waste. (ok, their poo.)
Its still humorous, but also interesting! And has pretty nice illustrations. I have Danzel at Silver Shoes and Rabbit Holes to thank for pointing me in Nicola Davies' direction - her books are great!