Where is that? And why are they spreading?
South Carolina, a bit above the easternmost green area in the US. Sounds like it's a combination of their lack of predators and high reproduction rate that's allowing them to expand. Wikipedia goes into a bit of detail:
en.wikipedia.org
I've posted about this here before, but as a kid in the 90s it was always an exciting novelty to see dead armadillos on the side of the road when my family would travel down south to Florida. In either 2009 or 2010, I saw my first dead armadillo in my hometown, and it was a huge "what?" moment. Now I see them daily, often multiple times daily, sometimes even in my own neighborhood. Seeing live ones is a lot less common, particularly since they're nocturnal, but it does happen from time to time too. It's been fascinating to see this expansion happen in real time over the course of my life.