Uhm? yes?
Not just the zoo, the whole earth is (for now) covered with life and all its fun excretions. With every breath, bite, and sip you take you will be consuming all kinds. We are covered in it, drenched, fed on it, we are part of it and it is part of us!
If you think this is a problem it is I think the only one the right-wing can be trusted to solve if you let them 
