We all have a "bee-Bo", why not write a book about it? "Belly Button Book!" is a silly story about a momma hippo and a baby hippo. Momma hippo is telling the reader about how baby hippo calls her belly button "bee-Bo"- how cute! And where do bee-bos come out to play? The Belly Button Beach of course. I love how Sandra Boynton takes a topic that might confuse children, the exposure seen at the beach in comparison to normal clothes, and makes it very understandable. Bathing suits are just a way of showing off your belly button. When Momma hippo refers to belly buttons, baby hippo is saying "bee-Bo" somewhere small, else where on the page. This is a sweet little detail! The illustrations are simple, matching the language. This a cardboard book, great for any young child. Check out "Tickle Time", another fun-loving rhyme picture book by Boynton.