Fleas are remarkable jumpers: They can travel 200 times their own body length in a single leap, and can withstand acceleration forces of 100 Gs. But exactly how do they make such incredible jumps? Although we’ve known for decades that fleas store energy in a springy protein called resilin before they launch into the air, it’s remained a mystery whether they use the flea-equivalent of feet (called tarsi) or knees (called trochantera) to transmit that energy to the ground. But with 21st-century high-speed cameras, researchers have now put the debate to rest: the answer is in the feet.
Now, the first task in experimenting with fleas is to find fleas. Luckily, the warmhearted individuals at England’s St. Tiggywinkles Wildlife Hospital Trust have flea-ridden hedgehogs just waiting to lose a few bugs–and so that wonderfully named hospital donated a few fleas to a good cause.
The study, published in the Journal of Experimental Biology, included both video and flea-leap simulations. But the researchers–led by Gregory Sutton at the University of Cambridge–made their first insights using the same methods that were used decades ago: