Tech history is full of famous rivalries: Microsoft vs. Apple, Google vs. Apple, Samsung vs… errmm… Apple. But two companies—neither of which make iPhones—that are increasingly at each other’s throats are Facebook and Snapchat, mostly because the former keeps stealing the latter’s features.

Yesterday, Snapchat used April Fool’s day as an opportunity to kick its rival as it suffers from the fallout of the Cambridge Analytica scandal. But rather than mock its questionable data collection practices, Snap exploited one of the social network's other controversies: Russian bots.

The photo- and-video-sharing app rolled out a new filter that copies Facebook’s user interface, right down to the colors and icons. But the text has been changed to look like Cyrillic—the Russia alphabet. First discovered by The Verge, the filter adds ‘likes’ from “your mom” and “a bot.”

The “mom” part is a dig at Facebook’s large number of older users—the social network might be the biggest in the world, but it continues to lose younger audiences to newer, cooler platforms like Snapchat. The company used the same joke in its April Fool’s filter last year.

The rest of the new filter is, of course, a reference to Facebook’s Russian bot problem. It’s thought that around 126 million of the platform’s users may have been exposed to Russian ads designed to influence the 2016 US election. The filter was only available yesterday, but don't worry if you missed it: Snapchat will doubtlessly show off something similar next April Fool's day.

Snapchat has reason to take aim at Facebook, admittedly. Mark Zuckerberg’s company has copied its rival’s Stories, Streaks, filters, and camera features in the past, leading to several public spats between the two tech giants.