A flea can jump over 150 times its own body length thanks to a built-in 'super-spring' in its legs.

In 2011, researchers Dr. Gregory Sutton and Professor Malcolm Burrows at the University of Cambridge used high-speed cameras to solve the mystery of how fleas jump. They studied the cat flea and found it could leap 33 centimeters high and 50 centimeters long. For a tiny flea only 2 millimeters big, that is like a human jumping over a 30-story building.The secret is a rubbery protein called resilin found in a part of their body called the pleural arch. Resilin is the most elastic material known on Earth. It can return 97 percent of the energy stored in it when it is released. The flea slowly squashes this protein like a person pulling back a bowstring to store up massive amounts of power.When the flea lets go, it shoots forward with a force of 135 g. This means it feels 135 times the pull of gravity. To put that in perspective, a human fighter pilot might pass out at just 9 g. The flea reaches its top speed in only one millisecond, which is much faster than you can blink your eye.The cameras showed that fleas actually push off the ground with their toes to get the best grip. This efficient system allows them to hop onto passing animals in an instant. Without this special spring, their tiny muscles would be way too slow to make such a giant leap.