At least five members of Twitter’s Cortex artificial intelligence group have left this month, at a time when companies are rushing to accumulate AI talent.

Earlier today, Kevin Swersky tweeted out a photo of his laptop and Twitter badge, indicating his departure.

Two days earlier, Jasper Snoek and Alex Wiltschko had done the same thing.

https://twitter.com/awiltsch/status/800799774773362688/

On Monday, Google announced that a key member of the Twitter Cortex team, Hugo Larochelle, had been selected to head up the company’s new artificial intelligence and deep learning division in Montreal. Larochelle shared his badge and MacBook photo on November 11.

And Ryan Adams did that, too, on the same day.

All five joined Twitter following the social networking company’s acquisition of startup Whetlab in 2015.

More recently, Twitter acquired AI startup Magic Pony.

Apple, Amazon, Facebook, Google, and Microsoft have all been hiring people from other technology companies and universities to bolster their AI capabilities.

Twitter declined to comment.