What is with all the bad reviews? James Patterson is a phenomenal writer and Zoo is defiantly a different take on anything he has written before but it is so good. The detail, research, and character development, and don't forget the humor help create a realistic story that made you wonder, could this happen? Perhaps that is why people dislike it, not the realistic aspects of the story but either humans low on the food chain or the brutality that is done to protect human beings. With that being said, this isn't a book for someone who is gun-how PETA you'll just burn the book and I am firmly against burning books. 
 The book is sad at times but it's made to be. Patterson is showing how humans have fallen away from nature and moved further into technology causing a kind of anarchy brought on by mammals. It becomes harder to read once this behavior reaches man's best friend and I'm sure this is where the negative reaction of some reviewers is coming from. If you can't see past this and not see the big picture that is being told, then perhaps you need to just step away and go read something else. 
 I for one enjoyed this book greatly. Yes, there were times that I wanted to stop and back away but I wanted to know more so I ended up continuing until the end. I didn't find myself rooting for humans nor animal but more felt like an on looker with no ties to anything and only seeing a story being told in such a magnificent way.