It’s raining worms in Northeast China—at least, that’s what some Twitter users think.

The theory was sparked by a viral video filmed in Liaoning, a Chinese province that borders North Korea. The footage was taken on a busy street, where a row of parked cars appeared to be covered with small cylindrical. Pedestrians could be seen in the backdrop while holding umbrellas, leading some to believe a “worm storm” had occurred.

According to the New York Postsome experts suspect the worms fell onto the town street after being swept up by heavy winds. Others immediately dismissed the “worm rain” reports as a hoax, claiming the cars were actually covered with poplar flowers, which resemble elongated insects, such as caterpillars. 

Local officials have yet to comment on the viral video.