Chickens, horses, and many animals have spread around the world far from their ancient homes. But sometimes, new predators and plants can have a big impact on the ecosystems that balance life on our planet. Readers discover how humans’ movements have impacted biomes, introducing invasive species that have brought some native species to the brink of extinction. This fascinating book gives readers a compelling look at the science and historical contexts behind invasive species, and shows them through detailed photographs and many vivid examples how plants and animals battle for resources against unwanted competition.