THE JOURNAL OF EXPERIMENTAL BIOLOGY, GRACE C. WU ET AL. A mite, Paratarsotomus macropalpis, was recently clocked at 322 body lengths per second, making the sesame-seed-size species the fastest land animal on Earth. The second-place animal is the Australian tiger beetle, which can scurry at 171 body lengths per second. Running a distant third is the cheetah, which tops out at a measly 16 body lengths per second. A human being would have to run about 1,300 miles per hour to match the mite’s body-size-adjusted pace.
Samuel Rubin, a junior at Pitzer College in Claremont, California, and colleagues announced the findings at the Experimental Biology 2014 conference in San Diego on Sunday (April 27) and in a paper in The FASEB Journal. “It’s so cool to discover something that’s faster than anything else, and just to imagine, as a human, going that fast compared to your body length is really amazing,” Rubin, a physics major, said in a statement. “But beyond that, looking deeper into the physics of how they accomplish these speeds could help inspire revolutionary new designs for things like robots or biomimetic devices.” The mite species was first identified in 1916, but little is known about its biology.
Rubin and his advisor, Pomona College biologist Jonathan Wright, used high-speed cameras to film the mites in the lab and in the Southern California desert, to which the species is endemic. “We were looking at the overarching question of whether there is an upper limit to the relative speed or stride frequency that can be achieved,” Wright said in the statement. “When the values for mites are compared with data from other animals, they indicate that, if there is an upper limit, we haven’t found it yet.”