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Study Reveals Squirrel, Not Rat, Made Chicago's Famous Hole

10/17/2025

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Summary

Story summary

A study published in Biology Letters concludes the "Chicago Rat Hole" was likely created by an eastern gray squirrel, not a rat.
Researchers from the University of Tennessee and the New York Institute of Technology analyzed photos to estimate 98.67% probability of a squirrel origin.
In early 2024, comedian Winslow Dumaine shared the hole on social media.
Visitors left offerings.
The researchers proposed renaming it the Windy City Sidewalk Squirrel.

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Story summary

A study published in Biology Letters concludes the "Chicago Rat Hole" was likely created by an eastern gray squirrel, not a rat.
Researchers from the University of Tennessee and the New York Institute of Technology analyzed photos to estimate 98.67% probability of a squirrel origin.
In early 2024, comedian Winslow Dumaine shared the hole on social media.
Visitors left offerings.
The researchers proposed renaming it the Windy City Sidewalk Squirrel.