In 2017, Facebook had to shut down two artificial intelligences that appeared to be chatting to each other in a strange language only they understood. The language was created by them but was incomprehensible to humans.

The two chatbots came to create their own changes to English that made it easier for them to work but remained mysterious to the humans that supposedly look after them.

The bizarre discussions came as Facebook challenged its chatbots to try and negotiate with each other over a trade, attempting to swap hats, balls, and books, each of which was given a certain value. But they quickly broke down as the robots appeared to chant at each other in a language that they each understood but which appears mostly incomprehensible to humans.