Drones can already find their way around obstacles, but they're usually looking for obvious obstacles like walls. What about navigating through tiny spaces where there may be just inches to spare? MIT has the answer. It just demonstrated tiny quadcopter drones using cutting-edge algorithms (the same ones used in the walking Atlas robot) to wend their way through a "forest" of 26 closely-packed obstacles. The trick is to flip the usual pathfinding routine on its head -- rather than plan a course based on the obstacles, the algorithms look for free spaces and string them together to create a safe route. As the video below shows, the result is a drone that zips effortlessly around poles and wires.