"An excellent introduction to classroom nature units and the perfect prelude to a walk in the woods." (Booklist) Cammy and William don't see any wildlife as they walk through the woods, yet there are signs everywhere that animals have been around. Help these young nature lovers find the clues--an empty nest, a fallen branch with the bark gnawed off, bleached bones by a cave, and more--and join in guessing "Who's been here?" In...