Small drones seldom last more than half an hour in the air due to their inefficiency. They frequently have short, thick wings that help them survive wind gusts, but are terrible for range. However, scientists might have a way to make drones last: borrow another cue from nature. Researchers at Brown University and EPFL have developed a bird-inspired wing design that can deliver just under 3 hours of flight for a tiny 100g (3.5oz) drone, four times what you'd get from comparable fliers, without sacrificing stability. Effectively, it recognizes that common wisdom surrounding wings doesn't apply when the wingspan is a foot or less.