Dolphins have long been a source of fascination for humans for their immense intelligence, charming personalities, and magnificent acrobatics. But there are lots of things that we don’t know about these captivating mammals: Did you know that there are 37 different species of dolphins? Or that dolphins drink milk? That they take naps? Or that some scientists believe that the dolphin’s ancestors once walked upright on land? Here, 3-D, layered models let children look through a dolphin's insides while they encounter interesting facts and vivid illustrations along the way.