I don't disagree, but there are species that invariably have more impact on their environment than others, and those species with inordinate amounts of impact o

I don't disagree, but there are species that invariably have more impact on their environment than others, and those species with inordinate amounts of impact on their environments, or nominal impacts in their native environment with non-nominal impacts in non-native environments are defined as 'invasive'. We fit our definition for the term. Like I said before though, I don't see anything unnatural about it myself.