"It's a lot less energy and effort to steal a rock than to go find one," deNapoli said. "They'll steal a rock from a neighbor's nest so they don't have to go hunting further away like down to the shoreline."
And with these two penguins (see video below), they will just keep repeating the pattern. Find the rock. Place the rock. Steal the rock. Over and over.
"That penguin is somewhat clever not having to work as hard," deNapoli said, referring to the video below. "He's pretty clever because he's taking a shortcut. He's just going to pinch rocks from the neighbor's nest."
Watch the underhanded mischief here: