books.google.com - Do dogs believe pictures of dogs are real? Why do dogs turn in a circle before they lie down? Can you trust someone your dog hates? Dog owners have questions; here are the answers to more than 200 of them, provided by two of the most knowledgeable writers in the field. Fun to read, eye-opening, and filled...http://books.google.com/books/about/Why_Do_Dogs_Like_Balls.html?id=uqe_I8Q83yAC&utm_source=gb-gplus-shareWhy Do Dogs Like Balls?