When Asian carp were first introduced into farm ponds in the southern United States during the 1970s, no one knew the harm they would cause in waterways as far north as Minnesota and Wisconsin! Today, these fish are just one of many invasive species that threaten native animals and habitats on Earth. There are many more animal invaders for readers to learn about, including bullfrogs, killer bees, and zebra mussels. The main content simply explains the harm caused by their presence, while full-color photographs allow readers to see the animals up close in their adopted habitats.