has launched a test of “fleets,” ephemeral tweets that self-destruct after 24 hours — a concept first popularized by Snapchat’s Stories.

Twitter said the new format is for “fleeting thoughts,” which users may not want permanently nailed up as tweets. Fleets will disappear 24 hours after they’re posted, and there’s no ability for others to retweet, like or publicly comment on them.

“One of the unique things about Twitter is that ‘what’s happening’ is fueled by people sharing their thoughts openly, through Tweets. But sharing your thoughts publicly can be intimidating!” Twitter product lead Kayvon Beykpour wrote in a post. “We’ve been listening to this feedback and working to create new capabilities that address some of the anxieties that hold people back from talking on Twitter.”

The company is launching fleets first in Brazil, “one of the countries where people talk the most on Twitter,” the company said. Twitter will evaluate the test-run of fleets in Brazil before deciding to take it elsewhere.

According to Twitter, an initial survey of users showed they would be more comfortable “sharing everyday thoughts” if they disappear after 24 hours.

Like tweets, Twitter fleets are based primarily on text, but you also can include videos, GIFs or photos in them. Users’ fleets will appear at the top of their home page and visible to their followers. Other users can reply to a fleet via private direct message or with an emoji.

Twitter is late to the disappearing-content game: Snapchat launched with the core feature of messages that delete after they’re viewed, and back in 2013 introduced Snapchat Stories that are viewable for 24 hours. Instagram launched a copycat in 2016 (a year after that Facebook itself did as well).

Twitter’s hope is that self-deleting posts will lead to more engagement by encouraging people to share more often — and to check their Twitter feed daily. Of course, fleets can still be screen-captured by other users. But the point is to provide a home on Twitter for expiring content in part to minimize users’ fears that controversial or otherwise embarrassing old tweets will come back to haunt them. Note that while Twitter lets users manually delete regular tweets, the text can remain accessible if those are “cached or cross-posted on third-party websites, applications, or search engines,” the company says.

The trial launch of fleets comes after Twitter last month acquired Chroma Labs, a startup founded by three ex-Facebook employees that developed an app for editing photos and videos posted to Snapchat Stories or Instagram Stories.

Beykpour shared an example of what Twitter’s fleets look like: