If you’re wondering what the kids are up to these days, look no further than TikTok -- a greatest hits for user-generated content in less than 15-second snippets.
It’s a popular app among young people where they post fun videos of themselves doing dance routines, acting out awkward scenarios and even singing to some tunes.
But recently the app has been attracting a much younger crowd.
According to Rick Floyd, an informational security officer in Greenville, South Carolina, the app has been extremely popular with elementary school students.
Floyd, who teaches kids about safe online practices, recently asked a classroom of fourth graders about how many of them use TikTok and almost a quarter of the 9-year-olds in the room raised their hands.
And he said that kids can get exposed to content darker than your average, funny TikTok video, and that kids are posting and watching suggestive videos, mature discussions, violence and profanity.
"I’m seeing language that is very inappropriate," Floyd told "Good Morning America." "Some of the videos, the way the kids are dressing is inappropriate. And that’s what our younger kids are seeing."
When ABC News scrolled through TikTok’s content, videos were found of teens talking about buying condoms, lying to their parents, sex with teachers, alcohol and drugs. The videos that rose to the top of the popular feeds featured buxom teens in bikinis and crop tops.
"You might not see anything objectionable, but there is a lot of profanity in the music," Christine Elgersma, senior editor for Parent Education, told "GMA." "There is some partial nudity. There’s a lot of provocative dancing. And contact with strangers really makes it better for older teens."