Dolphins are some of the most intelligent animals in the world, but scientists are learning that they may be even smarter than previously thought.

Using echolocation, which is the process of emitting sounds and listening for the echoes to navigate their surroundings, dolphins may be able to “see” the fetus in a pregnant woman, researchers have found.

Because echolocation involves ultrasound, or very high-pitched sounds that humans can’t hear, it’s possible that dolphins are able to map out a mental image of the unborn baby to see it just like doctors can.

In fact, at least one study has shown that dolphins can “see” objects hidden behind opaque barriers using echolocation, because they can easily translate what they hear into a mental image of the object.

“I think it’s extremely plausible [dolphins] would be able to detect a fetus,” Lori Marino, a neuroscientist at Emory University in Atlanta who studies cetacean intelligence, told Live Science. She adds, though, that “you’d have to really do a well-controlled study to make a definitive statement.”

Dolphins have also been shown to take a special interest in pregnant women, and they will sometimes swim up to a woman and begin making high-pitched buzzing sounds near her pregnant belly.

Malcolm Nicolson, a history of medicine professor at the University of Glasgow in Scotland, speculated dolphins may even be able to tell that a woman is pregnant by detecting the unborn baby’s heartbeat.

Marino also added that echolocation isn’t necessarily a skill dolphins are born with, but it’s instead a skill they learn over time. 

She explained that, just like humans, baby dolphins babble incoherently before they learn how to make more complex sounds. So it’s likely that as dolphins grow up, their language and echolocation skills improve and they’re better able to create mental images based on echoes.