A tiny creature no larger than an average sesame seed can run faster than any other creature, equivalent to a human running at around 1,300 mph.
The mite Paratarsotomus macropalpis has been observed running at speeds of 322 body lengths in a second. In comparison, cheetahs at their top speed of 60 mph can only manage 16 body lengths in a second.
Samuel Rubin, physics major at Southern California's Pitzer College, spent most of a summer doing fieldwork to record the mite's speedy accomplishments.
"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 says. "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 researchers used high-speed video cameras to document the mites' running prowess in the field and in the laboratory.
"It was actually quite difficult to catch them, and when we were filming outside, you had to follow them incredibly quickly as the camera's field of view is only about 10 centimeters across," Rubin added.
The smaller the animal the greater the stride frequency, the researchers report, although there was believed to be a limit to how quickly a creature's legs can be moved.
"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," says Rubin's academic advisor Jonathan Wright, a Pomona College biology professor.
"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."
The mite was first identified in 1916 and can frequently be found running across sidewalks and rocks in Southern California.
Despite being known to science for almost a hundred years, little is known about its food sources or its habits.
Mites can run across concrete as hot as 140 degrees F, well above what would be a lethal temperature for most animals.
"They're operating at temperatures that seem to preclude activities of any other animal group," Jonathan Wright says. "We've seen them running where there were no other animals visibly active."
Rubin presented the research team's findings at the Experimental Biology 2014 meeting in San Diego.
