The history of rat data in New York City is, in many ways, the story of a city’s ongoing battle with an enemy it can’t quite shake. Much like a persistent party crasher, the rats of NYC have always found a way to stick around, despite the city’s best efforts to show them the door. Before it became a city-wide enemy, the brown rat came to the US 300 years ago and wiped out the native black rat—revealing the ultimate winners of the rat race who, like Chief Keef, keep on winning.

This rodent saga stretches back to the 19th century, but it wasn't until the early 1900s that rats truly entered the public consciousness as more than just an unpleasant roommate. With outbreaks of diseases like the plague, the city began to take the problem seriously, although data collection at the time was more of a back-of-the-napkin affair than a sophisticated system.

By the mid-20th century, however, New York had turned its sights on sanitation. The 1940s and '50s saw a wave of urban cleanliness efforts, the rat equivalent of an eviction notice. Poisoning programs and more efficient garbage collection made a dent, but the records were sparse, largely limited to grim public health reports.

The Unwelcome Arrival: Rats Take Over the Big Apple

Then came the 1970s through the 1990s—a time when New York’s gritty streets were as much a habitat for rats as they were for people. The city saw a spike in rat populations, particularly in areas where trash piled up and infrastructure faltered. But it wasn’t until the launch of the 311 hotline in the early 2000s that citizens gained the power to call out their unwanted visitors in real-time. With every complaint logged, the city finally had a clearer picture of just how deep the infestation problem ran.

Fast forward to the 2000s, and the city embraced the 311 system as its most potent weapon against rats. Complaints became data points, and data points became maps—an elaborate game of connect-the-dots where the lines all led to garbage piles, subways, and park benches. The Department of Health even introduced a “Rat Reservoir Index,” as though the city’s rodent issue was now a geological feature that could be measured and studied like an aquifer.

But the 2010s saw the rat problem go from nuisance to national conversation. The city rolled out new technologies, from dry ice treatments to rodent birth control (yes, you read that right), and while the war on rats intensified, so did the complaints. By this point, every New Yorker had likely stumbled upon a rat on their commute, or maybe during an impromptu outdoor dinner.

Dialing Up the Fight: From 311 Hotlines to Data-Driven Warfare

Then came the 2020s, a period when the pandemic inadvertently invited rats to the party. Outdoor dining and a disrupted trash collection system served as a buffet for the city’s growing rat population. Complaints hit record highs, and the city responded by introducing a “Rat Czar”—an official tasked with leading the charge against this furry foe.

The city administration subsequently posted an advert for a director of rodent mitigation, offering a salary of up to $170,000 for someone “highly motivated and somewhat bloodthirsty” who was able to prove their commitment to “wholesale slaughter”.

The Rat Renaissance: Pandemic Surge and the Quest for Control

Today, the city’s open data initiatives allow anyone to track rodent infestations through public portals, offering both transparency and a grim reminder that, in the end, the rats are still winning. SVN and DeSciNYC are partnering to look at the data from various sources to make sense of this for the data illiterate. Not that this solves the problem because we are definitely losing. 24% of New Yorkers said they think that the rats run the city. For now.