In 2017, Michael H. Parsons finally secured a site to study rats in New York City. You would think that’s easy in Pizza Rat’s native land, but Parsons, a visiting researcher at Fordham University, says the process took “blood, sweat, and tears”: Since rats in New York invariably live on somebody’s property, that somebody has to let rats roam free for scientists to observe. Most people—if they’re going to let the scientists in—want the rats dead.
So it was a big deal when Parsons managed to convince a Brooklyn recycling plant to host his team’s research on rat pheromones, which are invisible chemicals that affect rodent behavior. Parsons and his team set up motion-triggered cameras around the plant. They carefully microchipped the site’s rats under anesthesia. And they set out pheromones to start collecting data.
Then, the cats came.
For scientists who try to control every possible variable in their experiments, the cats could have been a disaster. There were five to seven felines, all feral. Parsons thinks they were drawn to the pheromones the research team was using in the recycling plant. He didn’t want to scrap the research project, so he and his team decided to roll with it: They would now study how cats affect rat populations.