You know fireflies glow in the dark, but did you know there are many other animals that make their own light? Dive deep into the ocean, soar high in the sky, and explore the forest and desert floors to discover animals that glow.Explore the wonderful world of bioluminescence and biofluorescence in this National Geographic Kids Co-reader. Learn how and why animals emit light. Discover their incredible colors in stunning photography of eels, corals, frogs, and more.National Geographic Kids Readers have been a hit in the beginning reader category, and this book builds upon that success with a new approach—parents and children reading together. With the same combination of careful text, brilliant photographs, and fun approach to high-interest subjects that has proved to be a winning formula with kids, National Geographic Co-readers provide one page of adult read-aloud and one page of kid read-aloud text on each spread, building toward a collaborative reading experience.Series Overview: This high-interest, educationally vetted series of beginning readers features magnificent National Geographic images, accompanied by textwritten by experienced, skilled children’s book authors. Each reader includesinteractive features in which kids get to use what they’ve learned in the book. Level1 books reinforce the content of the book with a kinesthetic learning activity.Level 2 readers feature slightly higher-level text and additional vocabulary words.Level 3 readers have more layers of information to challenge more proficientreaders. For emerging readers, the Pre-reader level introduces vocabulary andconcepts, and the Co-reader level provides a collaborative reading experience.