Researchers have decided that a potentially good way to prepare for future contact with extraterrestrial beings is by studying…whale bubbles.

No, it’s not a joke—researchers from the SETI Institute, the University of California, Davis (UC Davis), and several partner institutions recently published a paper describing humpback whales blowing bubble rings during friendly interactions with humans. While this might not seem like a shocking action, the behavior provides insight into non-human intelligence, with important implications for our ongoing search for alien life.

“Because of current limitations on technology, an important assumption of the search for extraterrestrial intelligence is that extraterrestrial intelligence and life will be interested in making contact and so target human receivers,” Laurance Doyle, SETI Institute scientist and co-author of the study published last month in the journal Marine Mammal Science, said in an institute statement. “This important assumption is certainly supported by the independent evolution of curious behavior in humpback whales.”

While researchers had previously documented humpback whales creating bubble nets to capture prey and using bubbles to vie for female whales, the study examines the cetaceans blowing bubble rings during amicable interactions with humans. Doyle and his colleagues studied 12 bubble ring events involving 11 whales and 39 rings, behaviors that may represent playfulness or an attempt at communication. Jodi Frediani, a co-lead author of the study and marine wildlife photographer affiliated with UC Davis, explained that humpback whales frequently interact with boats and even swimmers in a curious, friendly way.

“Humpback whales live in complex societies, are acoustically diverse, use bubble tools and assist other species being harassed by predators,” added Fred Sharpe, also a co-lead author of the study from UC Davis. “Now, akin to a candidate signal [from extraterrestrial life], we show they are blowing bubble rings in our direction in an apparent attempt to playfully interact, observe our response, and/or engage in some form of communication.”

Chances are that, should we ever establish contact with extraterrestrials, their form of communication won’t be what we expect. By analyzing intelligent nonhuman communication systems—such as whales blowing bubbles while engaging with boats and people—scientists can broaden their understanding of unfamiliar forms of communication and refine what we should look for in our search for life beyond Earth. The goal is to be better prepared if or when contact occurs. Simply put, whale bubbles can be an analog for an alien language.

Their approach is the latest in a host of efforts to simulate extraterrestrial scenarios and hypothesize how we might ultimately come into contact with an alien species.