Invasive species--such as feral swine, stilt grass and the emerald ash borer--damage forests, grasslands, marshes, and farmlands. They may also cause harm to humans. Invasive species are non-native weeds, insect pests and other organisms introduced intentionally or accidentally by people who move them from their native range.
In the United States, economists estimate that more than $120 billion are lost annually to damages associated with invasive species. Invasive species threaten native plants and animals and their habitat in forests, marshes, and other natural areas.