The researchers got their inspiration from plant parts that are naturally more difficult for insects to climb. The scientists examined different plant bits, as well as glass and synthetic materials they'd made to mimic plant surfaces. Then they attached tiny harnesses to Colorado potato beetles (Leptinotarsa decemlineata) and measured the beetles' traction against each of the different surfaces. It turns out that the best surface structure for repelling beetles has tiny folds just half a nanometer in length and half a nanometer in height. The folds reduce how much contact the beetles' leg hairs make with the surface.