The complicated human relationship with rats is well-documented on social media — where wild, urban rats in cities like New York occasionally go viral for their consumption habits, audacity, or predilection for consuming human food.
First, there was Pizza Rat — so-named because the wild rat was filmed in a now-viral video carrying an entire slice of pizza down the subway steps, while an onlooker says "live your best life." (Pizza Rat was later revealed to be a hoax perpetrated by a performance artist named Zardulu.) In 2016, Pita Rats — two rats fighting, or perhaps sharing, a piece of pita bread — achieved similar virality. And in 2021, a video of a solo rat dragging a (thankfully, dead) crab through the subway tracks was viewed by hundreds of thousands.
But these city rats, though famous to online humans, are strangers in their own worlds, according to one rat expert. Indeed, the rats that you see by themselves, wandering around the built human environment, are technically the "losers" within their own social hierarchy. And though we find their food-dragging antics cool, their rodent peers certainly do not. Understanding why requires a little foray into the world of rats.
What is it like to be a rat?
Many of us have had, or at least played with, pet rats at some point; or, perhaps, you have worked in a scientific laboratory with lab rats. Yet lab rats and domesticated rats, the types of rats most of us interact with directly, are very different from the types of "wild" rats that you might see in a subway station scrounging for food.
"When you see an individual rat that is scrounging around in public or in broad daylight, or walking across someone's shoe, you're seeing what people might characterize as 'more desperate, disenfranchised' rats."
"The wild rat is as different from the lab rat as the chihuahua is from the wolf," quipped Dr. Michael H. Parsons, a rodent behavior expert, urban field ecologist and visiting research scholar at Fordham University in New York.
"Most of what we know about rat behavior and their direction and navigational skill capability is from lab rats in captivity, but that information from wild rats is incredibly limited," Parsons added.
The most common wild urban rat is the Norway rat (Rattus norvegicus), which are prolific reproducing machines, and rats reach sexual maturity in a matter of weeks. On average, a rat couple can create a resident rat population of 1,250 rats in just 12 months. Under nurturing human care, rats can live up to four years. In contrast, street rats may live half that time—about two years on average. And the outcast rats, like the crab-dragging fellow, perhaps even shorter.
"Rats are intelligent, sentient animals. They are capable of complex feelings and emotions, they feel remorse," said Parsons, a behavioral scientist who specializes in academic research relating to rat pheromones. Parsons clarified that rats, which are believed to have helped spread the Black Plague in the 14th century that killed 50 million people, are a public health hazard. "You need to take rats seriously because they can make you really sick," Parsons added.
Parsons said rats can be grouped into a social structure that maps onto three main groups: the alpha rats who are in charge of a well-organized rat colony; the beta rats who are part of the rat colony; and the omega rats who are not part of any rat colony. The latter are the so-called ostracized or "loner" rats. And these omega rats are the ones you're most apt to see in front of you on the street or in the subway.
Meet the omega rats
Parsons notes that alpha wild urban rats are the highest-ranking members of their large colony and are often well-groomed and have access to the best foods. He has observed rare "movie-star" rats who possess "excellent symmetry and beautiful, healthy coats, and they looked far better than the average rat most New Yorkers see."
In contrast, omega rats are the low rung on the totem pole, Parson said. In big cities, most people are most likely to encounter the omega rat in the street or, say, in the subway.
Instagram-famous rats also fuel misconceptions about rat behavior, Parsons said. Indeed, such rats are exceptions, not the norm — and typically are outcast rats.
"These are the vagabonds. These rats are desperate for food. They have to take risks. Things are not going well for these rats."
"When you see an individual rat that is scrounging around in public or in broad daylight, or walking across someone's shoe," Parsons said, "you're seeing what people might characterize as 'more desperate, disenfranchised' rats looking for new food sources," he said.
"They are the ones that have been forced to travel greater distances in order to find food. When humans see these rats, some may have been shunned — or even ejected — by their rat colony," said Parsons. "They are not well-groomed. These are the vagabonds. They are the scraggly-looking rats you might see in public. These rats are desperate for food. They have to take risks."
"Things are not going well for these rats," Parsons continued.
These so-called disenfranchised rats, Parsons said, are the ones that come to mind when people say "never corner a rat." If you've ever seen a wild urban rat backed into a corner (and hopefully you have not had that experience first hand) these rats will usually find a way out. Urban legend dictates that wild urban rats can jump at you and bite your face — if you are close enough. While it does happen occasionally, this is merely a rat's reaction to a fight-or-flight scenario.
But some rats, especially the sick or diseased rats, will most likely find a way to exit stage left whenever possible. In fact, alpha rats are unlikely to be out and about in public by themselves on a solo trip. Rather, the "alpha" rats tend to travel in groups, just as any popular high school kid would.
Whether you are dealing with an angry alpha rat and its posse or an hungry omega individual rat in the urban wild, be very careful either way. The average Norway rat can potentially jump vertically 3 feet, and horizontally 4 feet.
Parsons adds the majority of urban wild rats do not cover a very broad area geographically speaking — unless they are forced to. The average rat only travels only 30 meters, less than half of one city block, from its home base, he said. If necessary, rats can travel miles in order to get to a new food source, Parsons said.
According to Parsons, the rats that are traveling individually farther away from their homebase are the rats that are more likely to have been ejected from the rat colonies.
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"They have to take risks," he says. "During the pandemic, restaurants were closed and the rats had to take risks because their regular food source was gone."
One potential scenario that requires further research is the evolution of city rat colonies during the pandemic when restaurants closed. As rats ran out of food sources, they may have traveled further distances. Hypothetically, other rats, including omega rats, could have started out in or near the colony might find their way back, especially when the food sources depleted and the rat colonies dispersed or died out.
"We think this is what happened during and after the pandemic," Parsons said. "So that means it could be argued that not only do [wild] rats know how to find their way back to a specific location in the past, but they have a memory that that was a food source for them in the past."