Scientists have just made a remarkable discovery about whales that could totally change how we think about this still very mysterious mammal. Researchers found in a recent study that newborn humpback whales and their mothers will whisper each other when predators around to help each other escape, suggesting that they have a survival technique we weren’t even aware of.

Basically, the whales are trying to keep their communications from being intercepted by killer whales who could use that information to find the calf and kill it, according to a statement from Aarhus University. It’s an incredible discovery about a complex communication system not just between the same species, but between different species who act as predator and prey.

Whales give loud calls that reverberate for miles through the water, either to summon other whales or attract females, but scientists have never before seen such intimate communication between mothers and calves.

“We know next to nothing about the early life stages of whales in the wild, but they are crucial for the calves’ survival during the long migration to their feeding grounds,” lead author Simone Videsen of Aarhus University said in the statement. “This migration is very demanding for young calves. They travel 5,000 miles across open water in rough seas and with strong winds. Knowing more about their suckling will help us understand what could disrupt this critical behaviour, so we can target conservation efforts more effectively.”