Viral Phenomenon Cements UWI as the Authority on Urban Wildlife

Although the Chicago Rat Hole went viral a couple of weeks ago, it’s been viewable in Roscoe Village for 20 or 30 years. So it’s not new — and it’s also probably not a rat. But it’s certainly getting a lot of attention lately!

The imprint of a small mammal, captured in concrete near 1918 W. Roscoe Street, has been part of neighborhood lore for a long time. But, after a Twitter user named @WinslowDumaine posted the above image on January 6, the sight has been getting a lot of attention online, turning it into a legitimate viral phenomenon. Internet users have even given the “rat” a name, “Chimley,” and have started making offerings of coins and small items to the presumably ill-fated creature that is immortalized on the city sidewalk.

It’s certainly a better story to say that the animal imprint is a rat, thanks to Chicago’s reputation as “the rattiest city in the U.S.” (as calculated by pest control company Orkin). But new fans of Chimley may be doing the long-deceased rodent a disservice, just as Orkin may not be telling the whole story with its ranking — as Lincoln Park Zoo’s Urban Wildlife Institute pointed out last year.

All this attention has shown one major thing: UWI has become the authoritative source for accurate, scientific information about urban wildlife. Last year, when foxes began living in Millennium Park, members of the media came to UWI experts to explain the situation. National and local publications have turned to UWI to talk about possums, bats, ticks, and how climate change affects species. And the trend continues into 2024.

So what does UWI have to say about Chimley? Well, the animal probably wasn’t a rat, despite the appearance of the tail—which may have to do with how much lighter hairs are than bone.

UWI Director Seth Magle, Ph.D., told NBC this week that there are three reasons the Chicago Rat Hole is misnamed.

First, he said, the animal would have had to fall from a height to land that way on wet concrete, and a tree-friendly squirrel is much more likely to be in that position. Secondly, given construction schedules, it’s more likely that concrete would be wet during the day, when squirrels are active—and rats aren’t.

The third factor is basically the testimony of locals, who have told various publications, including the Chicago Sun-Times, that the imprint is definitely of a squirrel, and that a tree used to stand near that spot.

For all the details, check out Magle’s interview at NBC Chicago.