Please do not consider this as disrespectful or arrogant, but.... I live in Northern WI and we are experiencing some major problems with the native flora and fauna, and here it is, because of invasive earthworms.
I now this sounds silly but due to their very nature (natures composters) earthworms are eating plants and animals out of house and home.
I have seen data from studies showing the direct impact non-native earthworms have on local flora and fauna. They are actually to efficient at composting and have denuded mcuh of the vital leaf litter on our forest floors.
Moral of the story, just be careful your worms don't get away.