Instagram copied TikTok. Now it's swarming with TikTok videos.

• TikTok videos are aplenty on Instagram's Reels, a copycat feature it rolled out last year.
• A sizable portion of the videos on Reels is merely downloaded and reposted from TikTok.
• If user attention equates to advertising money, then TikTok videos on Reels benefit Instagram.

If you scroll through Instagram enough, you'll notice something out of place: lots of TikTok videos.

The short-form video app's content and creators seem to be all over the Facebook-owned app's copycat: Reels. And videos stamped with the TikTok logo - implying their first home may not have been Instagram-are regularly throws in front of viewers by Instagram's algorithm.

Some influencers appear to primarily use TikTok as a platform and have also turned to Instagram as a secondary stage.

And the online video trends that originate on TikTok slowly trickle down to Instagram, sometimes weeks after starting.

With so much content from the ultra-popular Gen-Z-centric app appearing on it, Instagram is benefitting from the videos - videos that started on an app that Instagram copied just last year.

Spill-over amongst social media apps is nothing new

It's not rare to see TikTok videos crop up on Twitter. Back when Vine was a thing (RIP,) the short videos would appear on YouTube.

But TikTok videos appearing on a competitor's copycat have their own implications, especially at a time when officials are watching tech companies like a hawk to see if they're engaging in anticompetitive behavior. (It's worth noting that TikTok copied Instagram too with its new Stories feature.)

TikTok has soared in popularity since it sprung onto the scene in 2016, spawning new content creators, so-called hype houses, and sometimes dangerous online trends. It had 732 million global monthly active users in 2020 and has been downloaded three billion times, a milestone that only Facebook, Messenger, WhatsApp, and Instagram have achieved.

Social media rivals took note of that success and created similar TikTok-like features on their own platforms. Snapchat rolled out a section called Spotlight in November 2020 that resembled TikTok's "For you" page. And Instagram launched its Reels tool in August 2020.

Users on Instagram can create short videos, and people can surf the many Reels via a designated button toward the bottom of the screen.

Some new videos appear to have been produced right from Reels. But other videos, bearing a TikTok logo, appear to have been posted on the video-sharing app, saved by the user, and then uploaded to Instagram Reels. That doesn't even include the videos that may have been first posted on TikTok that don't have the logo.

And there are videos that are known to have gone viral on TikTok that later appear on Reels.

If eyeballs equal money, TikTok is helping Instagram out

Social media companies make money by essentially selling people's attention to advertisers. So if Instagram users are consuming videos, many of which originated on TikTok, then the app is somewhat helping the firm turn a profit.

An Instagram spokesperson told Insider that watermarked content from outside Reels is allowed, but its research shows people don't love seeing recycled content, so it made changes to make it less discoverable.

TikTok did not immediately respond to Insider's questions about if TikTok videos appearing on Instagram violates its terms of service.

There do seem to be some trends specific to Reels, like a tool that lets you stitch together a bunch of photos into a video overlayed with a song.

But TikTok culture also seems to have become inextricably linked to the Reels platform, for better or worse.