Chicago's 'rat hole' sidewalk landmark was likely made by a squirrel or muskrat, researchers say

Researchers think they have debunked the origin of Chicago’s so-called “rat hole,” one of the Windy City’s weirdest local landmarks

Researchers think they have debunked the origin of Chicago’s so-called “rat hole,” one of the Windy City’s weirdest local landmarks.

Hold on. The rat hole wasn’t what you think. It wasn’t some back alley bar that served as a speakeasy for the city’s notorious gangster clientele or a tenement stuffed to the brim with junk. It was actually a full-body impression of an unlucky critter that got trapped in wet sidewalk cement in the city’s Roscoe Village neighborhood about 20 or 30 years ago. The imprint closely resembles that of a spread-eagled rat, complete with outlines of what appear to be tiny claws, arms and legs and even a tail.

The rat hole went viral early last year after comedian Winslow Dumaine posted a photo of it on X. The post drew curious tourists to the site at all hours, with some leaving coins and other odd objects around the impression as a tribute.

The constant traffic drew complaints from neighbors, though, and in April 2024 someone filled the impression with a substance resembling plaster. City workers eventually removed that slab of sidewalk and took it to the City Hall-County Building. A plaque honoring the rat hole remains at the actual site.

Chicago's iconic Rat Hole along the 1900 block of West Roscoe Street on Jan. 19, 2024.Tyler Pasciak LaRiviere / Chicago Sun-Times via APResearchers hailing from the University of Tennessee, New York Institute of Technology College of Osteopathic Medicine and the University of Calgary published a paper Wednesday in the journal Biology Letters that concludes the rat hole was most likely created not by the titular rodent but a squirrel or a muskrat.