It may well be they are referring to cornsnakes which are native. Many people here call the cornsnakes "ratsnakes", and specifically call yellow species "rats" while reddish ones are "corns".
I assume since they presumably eat rats in the corncribs, they call them both.
So he would be possibly referring to releasing a CORN snake which would be native, and if referring to a rat, at least he got the country right in saying ratsnakes are native to the US(at least some are, most folks not knowing there are many species of ratsnake from all over the globe)
At least that retic looked pretty healthy, and couldn't have been that aggressive the way it was lying over his shoulders and not constricting. Surprising to me when he had it in a tight grip behind the head.