Though the subways were badly flooded by Hurricane Sandy, the ratpocalypse that threatened to destroy humanity (at least in New York) and which has caused widespread panic among denizens of the Surface World has yet to materialize. "We haven’t seen an increase in rats above ground caused by Hurricane Sandy," Sam Miller, assistant commissioner for public affairs at the city's Department of Health and Mental Hygiene tells us.
In fact, the flood may end up as a net positive, as far as we people are concerned. "Flooding often displaces rats but also drowns young rats in their burrows and can reduce the rat population," Miller says.
As for the rats that did escape an untimely, watery death, Miller insists that "no research has demonstrated an increased health risk from flushed rats from underground." They may pose a risk to your job security, however, particularly if you work at a greasy spoon.