Are all invasive species alien, exotic, or foreign?
Not necessarily. In invasive species terminology, the words alien, exotic, and foreign are often used interchangeably and mean not native to the habitat in question. Some invasive species are native species that naturally occur in a habitat but are experiencing a population explosion in response to an unnatural influence such as disturbance by humans (dandelions can cause economic harm even where they are native). “Invasive” in its narrowest sense simply describes a species that is causing harm to other species. Invasive species can be alien to an environment or habitat, to a state, or to an area of an ocean, for example. Both the US government and this Web site use the term “invasive species” to mean invasive alien species.
