Facebook chose to shut down two robots this past week after they began to communicate in their own "language" while working through a negotiation role play. They were having the robots "barter" for items such as hats, balls, and books; each of which were assigned a value. Although when looking at the text conversation it doesn't seem to make much sense, the robots continually stressed their own names, seeming to be a part of the negotiations. The robots would even "place interest in one specific item - so that they could pretend they were making a big sacrifice by giving it up."
This isn't the first time artificial intelligence has made up its own language in an effort to improve efficiency - "Google revealed earlier this year that...its Translate tool had created its own language to translate into then out of." In this instance, Google chose to continue to let the AI run, citing it was happy with the development. Seemingly futuristic, one linguist says it's "unlikely the language is a precursor to new human speech" specifically due to its text based foundation rather than spoken.