First Posted: Apr 28, 2014
You might be surprised when it comes to learning what the fastest land animal on Earth is. It turns out that a tiny mite holds the new record for running speed as measured in body lengths per second. (Photo : Flickr/Martijn Munneke)
The mite in question is called Paratarsotomus macropalpis. It's no bigger than a sesame seed, but can run up to 322 body lengths per second. In comparison, a cheetah running at 60 miles per hour only runs at about 16 body lengths per second. "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," said Samuel Rubin, one of the researchers, in a news release. "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."
As an animal gets smaller, both relative speed and stride frequency increases. In theory, though, there's a limit at how fast a leg can move. The researchers decided to take a look at this fact a bit more closely in order to determine if there was an upper limit to the relative speed or stride frequency that could be achieved.
The scientists used high-speed cameras in order to record the mites' sprints in a lab and in the field. They saw the mites running on concrete and stopping and changing directions extremely quickly. In fact, a human running at an equivalent speed would sprint at 1,300 miles per hour.
The findings could give scientists insights that could be relevant to bioengineering applications. For now, though, it's simply interesting to learn about a creature that can move so rapidly, even when it's so tiny.
The findings are published in the journal Experimental Biology.