A small bear frolics in autumn leaves. While she plays, “the forest did its work” as sap flow slows down and more leaves let go. When it’s time for a long nap, Bear sleeps, “and the forest did its work. … Bacteria and fungi grew, while earthworms nibbled and chewed. Beetles and mites and slug and snails munched, too.” Bear awakens in spring, surprised that the leaves she played in are gone. Mama explains it’s because the forest did its work. Bear waits all summer, enjoying the sun and rich soil, but eager for the fallen leaves to return. When they finally do, she jumps in, and the leaves crumble: It turns out Bear, like the beetles and mites and slugs, and deer and moles and shrews, is also helping the forest ecosystem. An author’s note provides additional information on the role many creatures play or can play—including young humans!—in this seasonal cycle of breakdown and renewal. The informative, language-rich story is paired with pleasing watercolor illustrations. (Ages 3-7)