There's an urban legend in New York City that there are as many rats as people in the Big Apple. There are about eight million people in New York City so that means the number of rats roaming the city is the same. A statistician challenged this urban legend though, coming up with a study offering a more realistic portrayal of New York City's rat population.
Published in the journal Significance, the study utilized data from rat sightings recorded by service and information hotline 311. There are 842,000 property lots in New York and out of these, 40,500 are infested by rats.
Study author Jonathan Auerbach, a doctoral candidate from Columbia University's Statistics Department, was able to determine the number of infested lots by comparing [pdf] rat sightings from 2010 and 2011.
Assuming that about 40 to 50 rats make up a typical colony, it was estimated that there are two million rats in New York City. Auerbach said, however, that this is an overestimation.
"This is because we treat every lot with at least one rat sighting as evidence that a full colony of rats inhabited the lot for the duration of the study period. However, it is possible that the territory of one rat colony encompasses several lots," he clarified.
So, New Yorkers, rejoice! The Big Apple does not have eight million rats. It still does have a rodent problem though, what with two million of Ben's family members running around the city.
New York City is not oblivious to the number of rodents in the city, launching an official anti-rat program this year. The city is allocating $611,000 for the program, targeting areas where rats congregate the most to successfully reduce their numbers.
However, some have said the City Health Department's efforts at curbing the rat population in New York is lacking.
"This is a rat race we're all losing and it's one that affects our quality of life. Our audit found that the Department of Health and Mental Hygiene wasn't managing its pest control program effectively, even as the number of complaints about pests grew," said New York City comptroller Scott Stringer.
Aside from launching an anti-rat program, the City Health Department also called on New Yorkers to help out, saying "a community effort works best, where everyone in the neighborhood takes steps at the same time to prevent rats from entering the buildings and to remove their food and shelter."