Humans make up new slang words all the time. And, it turns out, orangutans do something similar, though they don’t use words. 

Orangutans can’t talk, but they do use sounds to communicate. Scientists in the United Kingdom have found that orangutans often come up with new sounds. Like human slang words, these sounds often catch on and are used by other orangutans in the community.

In a study led by Dr. Adriano Lameira of the University of Warwick, scientists spent five years recording “kiss-squeaks” emitted by orangutans in various communities. Kiss-squeaks are sounds that orangutans make to try to scare away predators. Scientists once thought kiss-squeaks were hardwired, meaning they never change. But the recordings showed that new kiss-squeaks are invented over time. The recordings also showed that after hearing a new kiss-squeak, other orangutans sometimes begin to use it. 

If this sounds familiar, it may be because this is a lot like the way humans add new words to their languages.

Scientists already know that human language is shaped by social surroundings. In other words, we begin to use new words after seeing or hearing them from friends, social media, TV, and other sources. The study provides evidence that orangutan communication is somewhat similar. Dr. Lameira told The Guardian he believes that some orangutans will invent new sounds to “show off their coolness and how [much of a] rebel they are.”