Boston Dynamics, maker of fearsome animal robots, begins to shed light on its work

BOSTON – It's never been clear whether robotics company Boston Dynamics is making killing machines, household helpers or something else entirely. For nine years, the secretive firm -- which got its start with U.S. military funding -- has unnerved people around the world with YouTube videos of experimental robots resembling animal predators. In another, a small wheeled rover nicknamed SandFlea abruptly flings itself onto rooftops -- and back down again. A more recent effort features a slender dog-like robot that climbs stairs, holds its own in a tug-of-war with a human and opens a door to let another robot pass. Boston Dynamics has demonstrated little interest in elaborating on these glimpses into a possible future of fast, strong and sometimes intimidating robots. For months, the company and its parent, SoftBank, rebuffed numerous requests seeking information about its work.