Geomapping the Rats of New York

"Michael Mills, a veteran health inspector in New York City, helps create a map of the city you won't find in any guidebook: a rat map.

The city's rat map was first introduced a year ago, with an intensive pilot program in the Bronx. Mills and other inspectors scoured the streets, building by building, cataloging rat hotspots - places that show so-called active rat signs, such as lived-in burrows, fresh droppings, tell-tale gnaw marks on plastic garbage bags - in an effort to target rodent-control measures more effectively. That geocoding information was entered into each inspector's hand-held indexing computer and aggregated with similar data from all across the borough.

Today, rodent complaints by residents from all over New York are electronically pinpointed on the city's computerized rat map, which allows inspectors to track complaints and hotspots over time and determine how well rat-control efforts are working. The results, after just one year, should be music to the ears of most New Yorkers: When the pilot study began in the Bronx, inspectors found active rat signs on 3,100 of the borough's 39,000 properties. Preliminary results now show that 1,250 of those properties are rat-free. That's a 40% dropoff in infestations."