Facebook has shut down a chatbot project after two bots began conversing in a language that only they could understand.

Researchers at the Facebook Artificial Intelligence Research built bots earlier this year and tried to teach them to negotiate and trade, according to The Telegraph.

The two bots were supposed to learn how to trade balls, hats and books by assigning value to the objects and bartering. But when Facebook paired two of the programs together, named Bob and Alice, the bots started communicating in their own way, according to The Telegraph.

Here’s what the interaction between the two bots looked like:

“Bob: i can i i everything else . . . . . . . . . . . . .

Alice: balls have zero to me to me to me to me to me to me to me to me to me

Bob: you i everything else . . . . . . . . . . . .

Alice: balls have a ball to me to me to me to me to me to me to me

Bob: i i can i i i everything else . . . . . . . . . . . .

Alice: balls have a ball to me to me to me to me to me to

Bob: i . . . . . . . . . . . . . . . . . . .”

The bots had no instructions to use comprehensible English in their interactions, which allowed them to create their own “shorthand” language, according to The Independent.

“Agents will drift off understandable language and invent codewords for themselves,” Facebook Artificial Intelligence Research division's visiting researcher Dhruv Batra told The Independent. “Like if I say ‘the’ five times, you interpret that to mean I want five copies of this item. This isn’t so different from the way communities of humans create shorthands.”

The bots certainly won’t be taking over the world with their incomprehensible language. Once the bots’ shorthand is explained, the conversation is actually understandable, according to Gizmodo. The shorthand was a more efficient way of trading with each other.

However, when the bots chatted with humans, most people were not aware that they were speaking to a chatbot, according to CBS Los Angeles.