When my kids were little, nutrias would come up to the bank while we were feeding ducks at the park in Boerne. My girls would go tell there mom about feeding the monster rats. My wife has still never seen one and doesn't have any idea what we were talking about.
I have never seen them another other place, but I know some have an abundance of them.
"Man is still a hunter, still a simple searcher after meat..." Robert C. Ruark