Narwhals are a species of marine mammal. Called the “unicorn of the sea,” they sport long, single tusks that look like horns. They have long fascinated humans. Yet there is much we don't know about them. A new study aims to shed more light on Monodon monoceros (“single-tooth single-horn”), including figuring out what that hornlike tusk is for. A joint team of researchers from Canada and the US flew drones over pods of narwhals. They recorded the animals' behavior. The footage shows narwhals hunting, socializing, and, to the biologists’ surprise, playing. In several of the drone videos, scientists observed narwhals seeming to toy with char. That's a type of fish. “Narwhals were recorded ... using their tusks to hit, manipulate and influence the behavior of fish,” the team wrote in the study. The narwhals followed behind the fish. They tapped them with their tusks. When the char tried to dodge, the narwhals chased. But they didn't try to spear or eat the fish. “Seeing that these animals are not actually hunting the fish but exploring ... was really a game changer,” lead author Gregory O’Corry-Crowe told CNN. He is a marine biologist at Florida Atlantic University. Narwhal tusks are mostly found on males (though some females can sport them, too). They can grow up to three meters long. The tusks are actually a special type of tooth, rather than a horn like that of a rhino. Reflect: What is something in nature or the world around you that you’ve always wondered about? Gif of narwhal from GIPHY.