How Fleas Jump (and How High!)
Fleas are some of the most exceptional jumpers on the planet. In relation to the size of their bodies, they are virtually unrivaled in their ability to propel themselves, leaving many to wonder exactly how fleas jump.
Fleas' incredible jumping capability is how these wingless insects are able to get onto your dogs. Fleas have been observed jumping from approximately 38 to 100 times their body length, and up to 2 feet high. While they have 6 legs, their hindmost pair is the most important set of legs when it comes to jumping. Fleas bend the closest segments of their longest set of legs (their rear pair of legs) directly before jumping.
First, Some Flea Anatomy
Understanding the anatomical construction of their legs is helpful in understanding how fleas jump. Their legs are constructed of 4 segments. Extending from the body outward, are the coxa, femur, tibia and tarsus, respectively. The coxa is the first segment of the leg. This joins fleas’ legs to their bodies. The femur is the thick portion of fleas’ legs, containing the most muscle and connecting the trochanter (a joint that is roughly equivalent to a knee) to the tibia. The tibia is segmented, connecting the femur to the tarsi. Finally, the tarsi (roughly their equivalent of feet) are the portion of fleas’ legs that are farthest from their body.
In studies, it was observed that fleas’ trochanters sometimes appeared to make contact with the ground just before they jumped. However, it is now believed that the tarsi are the most integral segment in understanding how fleas jump.
Fleas create around 100 times more power than their leg muscles alone could generate, and they always spring their legs at the exact same time. They rely on energy stored in an elastomeric protein—resilin, to perform their spectacular jumps. The resilin in fleas’ legs is essentially a stretchy pad of protein that extends and contracts, propelling them great distances. It is elastic enough to withstand the force of the quick, snapping movement that fleas enact while jumping, but is able to resume its original shape after committing to a jump.
Stop Those Jumping Fleas
As intimidating as these miniature, parasitic Olympians are, neither you nor your dogs should yield to timidity. Rather, it is fleas that should be wary of jumping onto your dogs in the first place. There are plenty of products that protect your dogs and your home from fleas. There are also products that kill fleas, if they already have access to your dogs. Check out some options on the right.
by James Donatelli