Serious question, because I don't know. What is so special (or problematic) with human poo? There are way more animals, amphibians, reptiles, insects, birds, etc. that pee and poo all over the earth, it's part of a healthy ecosystem. So why is human pee/poo such an issue and treated as something to be totally removed from the ecosystem rather than finding viable ways to put it back into the natural cycle of things? Why can't I go out and crap in my backyard the same as the sheep do?