Originally native to the Caspian and Black Seas, zebra mussels are now widespread throughout the United States. Transported accidentally, these quickly reproducing creatures soon became a deadly invasive species. From zebra mussels to water hyacinths, invasive species are wreaking havoc on many ecosystems. In this accessible and informative book, young readers will learn about the dangers of invasive species, how they harm habitats, and what can be done about it. Real-world examples, simple language, and colorful photographs bring key science concepts to life for developing minds.