CHICAGO – What began as a curious sidewalk anomaly in Chicago has concluded with a scientific explanation, settling a year-long debate about the identity of the city’s most famous “rat hole.” A new study, published by the prestigious Royal Society, has concluded with a staggering 98.67% probability that the viral imprint was not made by a rat, but rather by a squirrel.
The peculiar mark, located on a sidewalk in Chicago’s Roscoe Village neighborhood, gained widespread news coverage and internet fame in early 2024. It was first brought to national attention via a headline-grabbing tweet by comedian Winslow Dumaine on January 6, 2024. The impression, resembling a rat caught in a full-body splat on wet concrete, had existed for potentially two to three decades before its viral moment.
From Sidewalk Oddity to Tourist Hotspot
Following Dumaine’s post, the Chicago “rat hole” transformed from a local curiosity into an unexpected tourist attraction. Visitors flocked to the site, turning it into an informal shrine adorned with offerings that included coins, flowers, candles, and even food and other eclectic items. The phenomenon even inspired a naming contest, with “Splatatouille,” a nod to the Pixar film Ratatouille, emerging as the winning moniker. The site witnessed proposals and even a wedding ceremony, solidifying its status as a quirky landmark.
However, the surge in popularity brought its own set of challenges. Residents in the vicinity began lodging complaints about the constant traffic, noise, and public nuisance created by the influx of visitors at all hours. These concerns ultimately led city officials to take action.
The Scientific Sleuthing Behind the ‘Rat Hole’
While the public readily attributed the imprint to an unfortunate rat, suspicions lingered among some locals and wildlife experts that a squirrel might be the true culprit. To settle the matter, a team of researchers from institutions including the University of Tennessee, the New York Institute of Technology, and the University of Calgary embarked on a scientific investigation.
Their methodology, detailed in the Royal Society’s journal Biology Letters, involved meticulously analyzing high-resolution photographs of the imprint. Using coins left at the site as a scale, the researchers estimated the dimensions of the impression. They then compared these measurements to museum specimens of eight potential small mammal species native to the Chicago area, including brown rats, mice, chipmunks, and various squirrels.
Squirrels, Not Rats, Likely Made the Mark
The scientific analysis revealed compelling evidence against the rat theory. The proportions of the imprint, particularly the length of the forelimbs, third digits, and hindpaws, were found to be too large for a typical brown rat. Instead, these measurements aligned closely with those of Eastern gray squirrels (Sciurus carolinensis) and fox squirrels (Sciurus niger).
Further supporting the squirrel hypothesis, researchers noted that concrete is typically poured during daylight hours, when squirrels are active, whereas rats are primarily nocturnal. The absence of discernible footprints leading to or from the imprint also suggests that the animal may have fallen from a nearby tree branch – a behavior more consistent with squirrels than rats. The study authors even proposed rechristening the landmark the “Windy City Sidewalk Squirrel” to reflect its likely origins.
The Imprint’s Final Chapter
In April 2024, amidst growing neighborhood complaints, the Chicago Department of Transportation removed the slab of sidewalk containing the “rat hole”. The slab was preserved intact and is currently stored at the City Hall-County Building, with discussions ongoing about potential future public display. While the physical landmark has been removed, a plaque honoring the original site remains as a testament to its brief but memorable reign as a cultural phenomenon.
The study’s lead author, Michael Granatosky, an evolutionary biomechanist, highlighted that the investigation, while lighthearted, underscores the value of scientific curiosity and method in understanding the world around us. What started as a simple viral image has evolved into a fascinating case study, proving that even the most unlikely subjects can become subjects of serious scientific inquiry, making this quirky news story a top contender for one of Chicago’s most talked-about urban legends.
