Billboard explains that the song's emergence in the chart now (the song was released in 2016) was due to a combination of the steady growth of those who stream it, and the drop-off in seasonal songs now that the holidays are over.
Enough kids watched the "Baby Shark" video in the past week to push the song into the top 40 of the Billboard Hot 100 chart.
If, by some stroke of luck, you're unfamiliar with the song from South Korean educational brand Pinkfong, then give yourself a pat on the back. It initially went viral in Indonesia and spread globally before becoming a hit here in the U.S. In the past week, the song was streamed in the US 20.8 million times.
The main lyrics, "doo, doo, doo", repeat while introducing members of a shark family, coupled with a simple dance make the tune flawless fodder for little kids, leading to countless viral videos of them dancing and singing along.
Jimmy Kimmel apparently isn't a fan of the wildly popular children's YouTube video, "Baby Shark". Even Ariana Grande isn't safe.