Cockroaches are nature’s crash test dummies. The scuttling insects don’t swerve when they see a wall coming—instead, they ram into it, using the force of the collision to launch themselves upward. Now, researchers are taking inspiration from these tiny daredevils to create their own wall-climbing bot. Most mobile robots tackle obstacles by first sensing and then dodging around or clambering over them. But the time it takes to make such a decision slows them down and limits their ability to move around at high speeds. So scientists developed a sensorless, palm-size robot with a soft, roachlike exoskeleton and six legs that they dubbed the Dynamic Autonomous Sprawled Hexapod. It can’t climb a wall—yet—but it can shift from horizontal to vertical movement by simply crashing into one, just like a cockroach, the researchers report today in the Journal of the Royal Society Interface. The biggest secret to the roach-bot’s success is its size—a mere 16 grams. As animals increase in size, they hit objects with more energy during collisions, making them more susceptible to injury. The researchers calculated that only animals weighing less than 1 kilogram would be able to use the cockroaches’ head-first collision technique. The new work, they say, could lead to the development of less complex, but more robust robots that can navigate complex environments at higher speeds.