What happens to the environment when alien plants or animals get there by accident? Award-winning writer Mary Batten introduces readers to the serious and ongoing environmental problems caused when alien plants and animals (or invasive species) are introduced into an ecosystem accidentally or deliberately. Describing various examples―from the release of the gypsy moth into the United States to the introduction of rabbits to Australia―Batten uses clear, readable text to show how these foreign intrusions have disturbed the delicate balance of local ecosystems. Nature and animal art specialist Beverly Doyle contributes eye-catching visuals "that almost seem to jump off the pages," and back matter includes a glossary and list of ideas that provide more information and ways to minimize human impact on local environments.