This book is so fun, so fresh, so colorful, and so jam-packed with helpful information. I find that this group of National Geographic Little Kids First Big Books (Animals, Why, and Dinos) does "reference" for preschoolers in a way that really respects their need for information, while still keeping the books lively and on level. We love them all, and my kids could pore over this book for hours, especially the funny Why Not pages, where they can identify what's wrong with the picture. I learned a lot too. Now I know why skin wrinkles in the tub!