I think the anamoles were all chased out of the tunnels by the first trains. They're nervous critters. However, I think there are a few resilient jalbadgers down there to this day.
(Sorry - there's nothing like a good pun. And that was nothing like a good pun)

On a serious note - This sort of information must be like gold dust for the folks who get their monthly commuter pass paid by their companies.