Special gait helps this six-legged robot outpace insects

If you think the bugs in your home are already too fast to squish, then you don’t want them reading this story. That’s because researchers have now discovered a simple way to make insects faster: Change the way they run. Usually, speeding insects have three legs on the ground at once—a so-called tripod gait—whereas horses and other vertebrates hit their top speeds with just two legs on the ground. Using a computer program, a neurobiologist and a group of robot researchers simulated tweaking the natural movements and physical characteristics of a fruit fly to see whether they could make it faster. The prediction: The fly would be speediest with a two-legged gait, particularly if it got rid of the sticky pads on the tips of its legs that are used for climbing. Sure enough, when the scientists applied the changes to a fruit fly–like robot, it was 25% faster than another robot using a tripod gait, they report today in Nature Communications. But the simulations also showed that the typical tripod gait was still the best way for fruit flies and cockroaches to maneuver over uneven surfaces and climb—good news for anyone worried about fast-evolving bugs.