Another interesting question from Artscape:
Are red wiggler worms invasive?
Just like kudzu, garlic mustard, or mile-a-minute can invade and prevent the growth of native plant species, non-native insects and other animals can take over local ecosystems. The questions of whether or not red wiggler worms could take over local ground hadn't really occurred to me until someone asked about it at Artscape.
I do keep the worms in a bin, but worms can get out (and I did dump my smelly compost in the woods that one time). I got worried for a minute, but considering that red wigglers prefer to live in decaying matter instead of soil, I didn't think that they would be able to live for very long in Maryland soil.
This site pretty much confirmed for me that an invasion of red wigglers isn't a concern:
Speaking of invasives, I think it would be so cool to become a "Weed Warrior." Basically you get trained to recognize invasive species, and then whenever you are taking a walk through the park you can help maintain the land. It would be even cooler to bring seed balls loaded with native plant seeds to leave in place after the invasive species have been dug up.
I will leave you with something fun I found when searching the term "Red Wiggler." There is a great farm in Montgomery County that employs folks with developmental disabilities. They have a CSA, a solar powered barn, and are having a tour THIS SATURDAY the 25th. Here's their blog for more details: http://www.redwiggler.org/