A mix of humor and fact keep the interest high in this creative take on the ever-popular subject of metamorphosis, in which a curious --- and inventive --- old caterpillar has an unusual technique for transforming into a moth. Gramma Tinker is an old, old caterpillar who lives at the end of a cherry tree branch. Leaf and Lou, ant friends who live and work nearby, like to visit her to hear about her latest inventions. One day, Gramma Tinker shows the friends what she calls her greatest invention yet: the Wingmaker 77. Gramma is busy preparing for an upcoming adventure, and Leaf and Lou can't imagine what it might be --- especially when Gramma mysteriously explains that she'll rest inside the Wingmaker for two weeks, and when she emerges she'll be “changed.” Leaf and Lou don't understand. Why does Gramma Tinker need to make wings? And why is she studying flying creatures to learn about flight? What's going on with Gramma Tinker? In this fun, unconventional picture book on the subject of metamorphosis, award-winning magazine writer Dave Cameron stokes children's imaginations about one of nature's wonders. Award-winning illustrator David Huyck's playful imagery of the cheerful and enterprising caterpillar adds to the appeal. The story highlights an intergenerational relationship, featuring a strong older character with an intense scientific curiosity and who delights in inventing. The final page explains the science behind the real Gramma Tinker: a tent caterpillar who lives about 77 days before making its cocoon and emerging two weeks later as a lappet moth. This is a great choice to add levity to life science lessons on growth and changes in animals, and also on the idea of being an inventor.