When humans dream of flight, they don’t often imagine jellyfish. But a new flying machine mimics the umbrellalike flapping of an ocean jelly . The prototype has a motor-powered crankshaft that alternately flaps opposing pairs of petal-shaped wings. Though its Mylar film and carbon fiber body weighs less than one-tenth of an ounce, its stability stems from its bottom-heavy design, which lets it wobble, but not flip over. Indeed, its designers argue that the flying jelly is more stable than robots based on insects or birds, which require a tail, sails, or a feedback system to stay upright. Researchers can adjust the speed and size of the flapping to make it hover or change directions. Though the current prototype must be plugged in, future models will be battery-powered, the team reports online today in the Journal of the Royal Society Interface. Such minidrones could do military surveillance or monitor traffic or air quality. Considering the advantages of jellyfishlike flight, the scientists question why no land animals have evolved to fly this way.