My kid is 3 and that’s the perfect age to start learning more about the world. And as a literacy teacher, to me nothing beats National Geographic for non-fiction. So I’ve started collecting this series in hardback (beautiful) for bedtime and anytime reading with my kid.The author of this series knows how to write for kids! The layouts are engaging, tons of captions- which are great for reading to excited kids who can’t quite understand the full paragraphs yet. The photographs are fantastic, highly detailed and interesting and the book length is substantial with a wonderful variety of animals explored. You can select a few animals for a bedtime read and there is so much to see that you learn something new each time. To me it’s more fun than fiction because you can skip around and read whatever your kid is interested in, while having great conversations about animals and environments, and how people do things in comparison with animals…on and on. It is not a passive experience for kids, they are very reactive to the content and will ask you questions. Sometimes we cue up a YouTube video (also National Geographic) if an animal really inspires us. The color changing of an octopus on video blew my kid’s mind. So, this book really helps you take time to teach your kids about the world. It would make a fantastic gift to any parent with young kids. They will want the whole series next!We took special interest in the map in the reference section, which is such a great knowledge base to start building with something as relatable as animals. My kid even wanted me to read him the table of contents, so all of those non-fiction features are laid out beautifully for kids.I expect these books (the series) to grow with us. They are written at maybe a late second grade level, early third. The language is simple, direct, and addresses the reader like a teacher of K-5. The tidbit facts are fun and mind-expanding for kids, not dry facts like books written years ago.The material and images are fascinating for even older kids (and adults reading them aloud!) So I’d say 3-10 year olds can enjoy these for many many re-readings. They’re a kid-library staple. So far we have the ocean animals book, transportation book, solar system book, bird book (lovely for kids watching birds out the windows) and this one. I hope they write a body book. For that I bought a DK book but it’s a higher reading level and we could use something younger right now but with real photographs. The solar system one is incredible. The images we have now are so clear, and understanding the concept of space is such a special thing to teach your kids yourself! I highly recommend the whole series!Let me know if this was helpful! :)