Learn why fireflies flash their lights in this glow-in-the-dark book based on the hit PBS Kids show The Cat in the Hat Knows a Lot About That! Sally and Nick are making shadow shapes when the batteries in their flashlight conk out. Luckily, the Cat knows where they can get some light: from his friend Shimmer, a firefly! But it turns out Shimmer needs some help of her own: her friend Glimmer is in trouble. Fireflies call to each other using unique flashing light patterns, and Glimmer's pattern is all wrong. He needs help--fast! Can the Cat and Co. un-stick Glimmer from a giant spiderweb AND find enough light to put on a shadow show? You bet they can! With glow ink on every other spread and two sheets of glow stickers, this is a fun way to celebrate summer and to spark discussions on how different animals communicate!