5 Bugs That Jump

The science behind their leaps

Jumping spider.
A jumping spider sends blood to its legs to extend them and fling itself into the air. Getty Images/Moment/karthik photography

Most bugs crawl, and many bugs fly, but only a few have mastered the art of jumping. Some insects and spiders can hurl their bodies through the air to escape danger. Here are five bugs that jump, and the science behind how they do it.

 

01
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Grasshoppers

Grasshopper on leaf.
A grasshopper's large hind leg muscles provide the force for it to leap. Getty Images/E+/CUHRIG

Grasshoppers, locusts, and other members of the order Orthoptera are among the most skilled jumping bugs on the planet. Although all three pairs of their legs consist of the same parts, the hind legs are noticeably modified for jumping. A grasshopper's hind femurs are built like a bodybuilder's thighs.

Those beefy leg muscles enable the grasshopper to push off the ground with a lot of force. To jump, a grasshopper or locust bends its hind legs, and then rapidly extends them until it's nearly on its toes. This generates significant thrust, launching the insect into the air. Grasshoppers can travel many times their body length just by jumping.

02
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Fleas

Flea.
Fleas snap an elastic pad to create the momentum to move. Getty Images/ Kim Taylor/Nature Picture Library

Fleas can leap distances up to 100 times their body length, but don't have beefy leg muscles like grasshoppers. Scientists used high-speed cameras to analyze the flea's jumping action, and an electron microscope to examine its anatomy at high magnification. They discovered that fleas may seem primitive, but they use sophisticated biomechanics to accomplish their athletic feats.

Instead of muscles, fleas have elastic pads made from resilin, a protein. The resilin pad functions like a tensed spring, waiting to release its stored energy on demand. When preparing to jump, a flea first grips the ground with microscopic spines on its feet and shins (actually called tarsi and tibias). It pushes off with its feet, and releases the tension in the resilin pad, transferring a tremendous amount of force to the ground and achieving lift-off.

03
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Springtails

Springtails in compost.
Springtails use an abdominal peg to hit the ground and spring into the air. Getty Images/PhotoDisc/Tony Allen

Springtails are sometimes mistaken for fleas, and even go by the nickname snowfleas in winter habitats. They rarely measure longer than 1/8th of an inch, and would likely go unnoticed were it not for their habit of flinging themselves in the air when threatened. Springtails are named for their unusual method of jumping.

Tucked under its abdomen, a springtail conceals a tail-like appendage called a furcula. Most of the time, the furcula is secured in place by an abdominal peg. The furcula is held under tension. Should the springtail sense an approaching threat, it instantly releases the furcula, which strikes the ground with enough force to propel the springtail into the air. Springtails can reach lofty heights of several inches using this catapult action.

 

04
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Jumping Spiders

Jumping spider.
A jumping spider sends blood to its legs to extend them and fling itself into the air. Getty Images/Moment/karthik photography

Jumping spiders are well known for their jumping prowess, as one might guess from their name. These tiny spiders hurl themselves in the air, sometimes from relatively high surfaces. Before jumping, they fasten a silk safety line to the substrate, so they can climb out of danger if need be.

Unlike grasshoppers, jumping spiders don't have muscular legs. In fact, they don't even have extensor muscles on two of their leg joints. Instead, jumping spiders use blood pressure to move their legs quickly. Muscles in the spider's body contract and instantly force blood (actually hemolymph) into its legs. The increased blood flow causes the legs to extend, and the spider goes airborne.

05
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Click Beetles

Click beetle on grass stem.
Click beetles right themselves by snapping their bodies against the ground. Getty Images/ImageBROKER/Carola Vahldiek

Click beetles are also able to go airborne, flinging themselves high in the air. But unlike most of our other champion jumpers, click beetles don't use their legs to leap. They're named for the audible clicking sound they make at the moment of lift-off.

When a click beetle gets stranded on its back, it can't use its legs to turn back over. It can, however, jump. How can a beetle jump without using its legs? A click beetle's body is neatly divided into two halves, joined by a longitudinal muscle stretched over a hinge. A peg locks the hinge in place, and the extended muscle stores energy until needed. If the click beetle needs to right itself in a hurry, it arches its back, releases the peg, and POP! With a loud click, the beetle is launched into the air. With a few acrobatic twists in midair, the click beetle lands, hopefully on its feet.

 

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