Study Finds DNA Differences Divide NYC Rats by Neighborhood

In addition to the iconic landmarks, multitude of cultures and cuisines, and powerful history, New York City is also known for one other thing: its rats. They’re are in the subways, dragging pizza down the stairs, fighting over french fries, in restaurants, and apartments. But while we’ve often just seen the rats as, well, rats, Matthew Combs, a student at Fordham University, has found that there are actually uptown rats, and downtown rats, divided from the center point of Midtown.

In New York City, the Rattus norvegicus, or brown rat, is the most dominant rat species in the city. Over the course of two years, Combs and his colleagues have been trapping the rats through bait made up of peanut butter, bacon, and oats, then cutting off an inch or so of their tails to sequence their DNA. Now, they have one of the most comprehensive guides of NYC rats in the world, and the results are actually amazing, even if you hate rats.

Because rats generally stay in the same area over the course of their lifetimes, the uptown rats don’t mix with the downtown rats; but more than this, they can actually be traced down to a neighborhood. In an interview with The Atlantic, Combs said, “If you gave us a rat, we could tell whether it came from the West Village or the East Village.”

Combs, whose twitter handle is @rattus_mattus, actually came to the city to study urban rats, and is now writing his dissertation on the ecology of rats in New York City. The guide is an integral part of this, as a main component of his dissertation is looking at how different characteristics around the city have effected the distribution of rats – or, basically caused the neighborhood differences between them. His “first first-author paper” on the rat population in New York City has just been published.

There actually used to be a pretty even mixture between the brown and the black rat species in the city, until the brown rats started attacking, killing and outcompeting the black rats for food and shelter. Rats can squeeze through holes the size of a quarter, tread water for three days, jump a distance of four feet, and fall from a height of forty feet, and survive. It’s been a long war of humans vs. rats, but the enemy is not without their skills.

Next, check out Fun Maps: Brooklynites Complain Most about Rats in NYC.