St. Petersburg, Florida is dealing with some cheeky new street art: a heck of a lot of graffiti butts, shakin’ their thing all over town.

The butts—simple line drawings, most made with black marker—display a distinctive form. “The silhouette of three ‘cheeks,’ so to speak, is the featured signature of the anonymous artist,” local news outlet WFLA politely explains.

The triple-tush has been spotted in at least twenty places in the city over the past few months—including pay phones, trash bins, and walls—after what the Tampa Bay Times described as a “butt spree.”

Thus far, no one knows who is behind the behinds. Law enforcement is keeping a sharp eye out, though:

“The bottom line is whoever is doing this is destroying property,” the assistant police chief, Jim Previterra, told WFLA. And if anyone knows about bottom lines, it’s probably the culprit.

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