It takes 40 muscles to frown, but only 15 to smile? Skin converts sunlight to vitamin D and is the largest organ of the body; and 200 eyelashes on each eye last 4 months! Little fingers and curious minds will be in awe of the ZooBooKoo Educational Human Body Cube Book as they learn facts and figures about the human body. With each turn, youngsters will learn more and more about the human body, covering all major body systems including the heart, lungs, water works and digestion. Eyes, ears, bones, muscles, blood, nerves and the brain! Satisfyingly fun & addictive learning for all ages With a tactile and fun design children of all ages (and even adults!) will be intrigued and ready to learn about the human body!