If you live in North America, you might have enjoyed the bright songs of black-capped chickadees or red-breasted nuthatches on your street. But you might not have known that those songs have lyrics.

“You might call them words,” says Erick Greene, an ecologist at the University of Montana, “but linguists might get upset about that.”

In fact, the chickadee has a vocabulary of around 50 distinct sounds that communicate a few essential phrases, like “danger!” “feed me!” or “I’m single!”

Greene and his colleagues have previously found that nuthatches eavesdrop on these chickadee warning signals and “retweet” them to their neighbors—like real-life Twitter, Greene jokes.

But their new research shows that like any good reporter, the nuthatch checks out its