A rat peeks out of a hole at a Brooklyn subway stop in 2005. (Photo: AP/Julie Jacobson)
With more than half a dozen of New York City's subway tunnels flooded from Hurricane Sandy, subterranean residents usually seen scurrying from one hiding place to another might have an extended stay on the surface, which has some concerned about the health implications.
National Geographic reported exterminator Benett Pearlman of New York-based Positive Pest Management Corp saying that although some rats may have died underground, it's probable that many escaped a watery grave. Things on the surface are probably looking pretty good to them too:
Sandy has brought a feast to their feet. New sources of food are washing out of the waterways and along flooded streets, including loads of rotting trash, other rats, pigeons, and fish. The well-fed rats will burrow beneath buildings under cover of night to establish new homes, sliding into holes as small as a half inch (1.3 centimeters)—the width of their skulls—even though their bodies can measure up to 18 inches (46 centimeters) long.
Bora Zivkovic has a very detailed blog post for Scientific American with various scenarios for how the rats would have died or survived. He also points out that some rats didn't even have to deal with the flooding because they were not in an area that went under.
"[..] my guess is that most of the rats survived,"Zivkovic wrote. "But quite a large number of rats drowned – depending on exact location, depth, how much they know how to get to the surface at all, their exact route to the surface, and their status in the social hierarchy."
With that, diseases and other health concerns associated with rats come into play. The Huffington Post reported Rick Ostfeld of the Cary Institute of Ecosystem Studies saying that rats are known to "exacerbate disease" if the population is high. Diseases spread through rat bites, feces or urine include hantavirus -- seen earlier this year in Yosemite National Park -- salmonella and the bubonic plague.
"A rat distrubance is something we should be concerned about," Ostfeld said, according to the Huffington Post.
HuffPost reported Ostfelt noting that high flood waters could also serve to dilute the disease pathogens associated with the creatures though and lead to less of a risk of contraction.
But these flood waters, National Geographic reported in a separate article, could contribute to illness themselves. Beyond driving out the rats -- those who made it -- there are several risk factors associated with the water. These include hiding dangerous objects -- like glass you could step on -- or being electrified from a downed power line.
Sewage brought up from the flood waters could pose an issue as well:
The most concerning urban bacteria is Escherichia coli—also known as E. coli—the organism that most mammals use for digestion. Found in the lower intestine, it can be toxic if ingested into the stomach. Floods that carry raw sewage into high density areas can spread the bacteria.
National Geographic reported University of Michigan Homer Nowlin Chair in Water Research Joan Rose saying there is almost always an uptick in illness after an extreme flooding situation.
Suggestions to prevent illness in this situation are to adhere to any boil water advisories, avoid walking in flood water and don't eat anything coming in contact with the water without properly cleaning it.