Researchers studying sperm whale communication say they've uncovered sophisticated structures similar to those found in human language.
In the inky depths of the midnight zone, an ocean giant bears the scars of the giant squid she stalks. She searches the darkness, her echolocation pulsing through the water column. Then she buzzes – a burst of rapid clicks – just before she goes in for the kill.
But exactly how sperm whales catch squid, like many other areas of their lives, remains a mystery. "They're slow swimmers," says Kirsten Young, a marine scientist at the University of Exeter. Squid, on the other hand, are fast. "How can [sperm whales] catch squid if they can only move at 3 knots [5.5 km/h or 3.5mph]? Are the squid moving really slowly? Or are the whales stunning them with their vocalisations? What happens down there? Nobody really knows," she says.