High-speed video reveals that fleas jump from the insect equivalent of their feet.
Flea knees never even touched the ground in about 10 percent of the jumps.
The footage resolves a long-standing debate over how fleas are able to jump so high.
A decades-old debate about how the animal kingdom's most renowned jumper jumps appears to be settled.
No, not rabbits or frogs. Fleas. Using new tools like high-speed video, researchers with the University of Cambridge in England have shown that fleas take off from their tibiae and tarsi -- the insect equivalent of feet -- and not their trochantera, or knees. The researchers report their conclusion in the March 1 Journal of Experimental Biology.
Regardless of how fleas do it, the insects have always been famous jumpers, says study coauthor Gregory Sutton. "There are even fairy tales that talk about how magnificent fleas are at jumping," he says. And it's not surprising -- fleas jump far. Some fleas -- only a few millimeters long -- can jump well over 10 centimeters, according to one study. Adult hedgehog fleas (Archaeopsyllus erinacei) go from resting to midair in about 1 millisecond, says Sutton, a mechanical engineer at Cambridge.