Three legs good, two legs better. At least, that’s the case if you’re counting the number a six-limbed robot should leave on the ground to move quickly.

Roboticists often borrow from nature when it comes to walking styles—but that doesn't mean the movements are necessarily the most efficient. Most insects leave three of their six legs on the ground as they scuttle, but they do so to ensure they maintain enough friction against a surface to allow them to climb slopes. Now, calculations published in Nature Communications by researchers from the École Polytechnique Fédérale de Lausanne in Switzerland reveal that leaving just two feet on the floor can make movement faster on the flat.

Testing that idea out using a robot modeled on a fruit fly yields results that speak for themselves: in the video, the top robot leaves three feet on the floor, while the bottom one leaves just two. The latter is 25 percent faster. When the insect robots of your nightmares chase you down, expect them to be coming faster than you expected.

(Read more: Nature Communications, “DARPA’s Robot Challenge May Equip Robots to One Day Walk Among Us,” “The Latest Boston Dynamics Creation Escapes the Lab, Roams the Snowy Woods,” “Agile Robots”)