Open up TikTok and there’s a good chance you’ll be confronted by a teenager in the bathroom.

Most home bathrooms are well lit and have nice, bright acoustics. Unlike the kitchen, living room or even bedroom, bathrooms are private spaces, where parents and siblings are trained to not barge in.

It’s almost inevitable that they would become the perfect stage set for the dramatic entrances, exits, skits, dances and story times of TikTok, the short-form social video app that has grown wildly popular in the last year.

Videos shot in the bathroom consistently outperform those shot elsewhere, many creators say. They call it “the bathroom effect.” Milli2nd, a 21-year-old music producer known for performing with a mirrored pyramid over his head, said he has shot the same video in multiple settings and the bathroom versions win. “Ones I’ve done in the bathroom get much more views,” he said.