Book excerpt: Flap book revealing everything you wanted to know about poo - and a bit more. Crazy but true, life on Earth can't exist without poo! Starting with human sewage then moving on to animal poo, this surprisingly charming lift-the-flap book explores what happens when we flush, what animal toilets look like, why animals don't need to flush and just how important poo is - for a myriad of fascinating (and sometimes yucky) reasons.