New video footage provided by researchers in northeastern Canada has shed light on how narwhals use their "tusks" in the wild, National Geographic reports.

For years, scientists have wondered why the rare whale has a massive, unicorn-like horn, which is actually a canine tooth that passes through its upper lip and pokes out from the head. The tusk-like feature may serve a variety of purposes, including as an echolocation tool, as a sensory organ (it’s covered in thousands of nerve endings), or for sexual selection. But now, experts know that narwhals also use their tusks as a hunting tool: They repeatedly jab Arctic cod with the sharp appendage, which stuns the fish and makes them easier to catch.

Adam Ravetch, a filmmaker with the World Wildlife Fund Canada and researchers from Fisheries and Oceans Canada used drones to film the elusive narwhal hunting behavior in Tremblay Sound, Nunavut, Canada. "This is an entirely new observation of how the tusk is used,” Brandon Laforest, an Arctic species and ecosystems specialist with WWF-Canada, told National Geographic.

Watch the giant whales hunt fish below.

[h/t National Geographic]