It's a big question--are parasites friends or enemies? From tiny organisms to fleas, ticks, and huge plants, parasites can have a huge impact on the animals and habitats around them, but are they more helpful or harmful? Discover how scientists study these living things and learn about . How microscopic parasites spread and feed off hosts without them knowing about it The surprising ways parasites can boost the immune system The modern, cutting-edge technology that's helping scientists understand these organisms . and so much more! Beautifully bound with stunning illustrations, this title is part of a unique and collectable series that will start a lifelong interest in science for kids. Each book in the series includes a QR code that links to The Big Question Answered website for comprehensive free teacher resources, kids' activities, and more!.