Back in '99, I visisted an ex girlfriend who was attending MIT. While waiting at one of the subway platforms, we observed a couple of mice running around down by the rails.
Last weekend I was in Boston again, and this time observed quite a few mice down by the rails in one of the subway stations.
They seem to be quite a long ways from the surface; I don’t know much about mice, but I’d guess they’re not making regular sorties up to ground level. No doubt water can trickle down to them from somewhere, but what are they eating? There’s no vegetation down there. Are there enough crackers and sandwich scraps getting tossed down onto the rails for them to eat?
While we’re on the subject, I visited Washington, DC last fall and again this spring. I don’t remember seeing any mice down there. Why does Boston have mice and DC doesn’t?