Late one night, ecologist Jonathan Martin was searching for tree frogs in his Wisconsin backyard when he made an unexpected discovery. As he shined an ultraviolet flashlight in the direction of a high-pitched chirp, Martin saw a flash of bright pink at his bird feeder. That pink glow was coming from a flying squirrel. What was going on? You’re probably familiar with some kinds of glowing animals. Fireflies light up summer nights. Bioluminescent jellyfish and other sea creatures fill our oceans. But some animals glow only under ultraviolet light. This is called biofluorescence. That flying squirrel Martin found turned out to be one of the first-ever recorded sightings of a biofluorescent mammal. Follow along with Martin and his colleagues as they delve into the mystery of the flying squirrels and discover that they aren’t the only glowing mammals out there! "Young explorers are encouraged to think critically, look at the varying perspectives of a new discovery, and seek out their own observations. A must-purchase for collections serving curious minds, suitable for upper elementary or middle grades." ―starred, School Library Journal "Stellar storytelling sure to make a citizen scientist out of any curious reader." ― Booklist Maria Parrott-Ryan is a writer and editor based in Madison, Wisconsin. She writes fiction, nonfiction, and educational material for both children and adults.