How Far Can a Flea Jump?
The ordinary flea can jump about thirteen inches. That is about 100 times the length of its body. If you jumped that well, you could spring the length of a football field in one or two bounds! The flea uses its jumping ability to survive. It is a parasitic insect — that is — one that lives on other animals.
The flea leaps onto a passing animal, hangs on with its sharp claws, and digs in. Its sharp mouth parts pierce the victim’s skin and suck the blood. The flea’s strong legs and flat body enable it to move quickly and easily through the hairs of its host.
Now Cambridge scientists have finally cracked the mystery of how the minuscule insects leap so well. ‘Their toes press on the ground, using the lever system of their legs. They have to grip the ground when they jump as they are using a huge amount of force.’
In most of the jumps two parts of the insects’ complicated legs – the toe and knee – were in contact with the ground during the push off.
When they looked at a flea’s leg in extreme close up using a scanning electron microscope the scientists saw that the shin and toe had gripping claws but the knee was completely smooth as the fleas pushed down through the shin onto the toe.
Their observations were confirmed with real, and mathematical models of a flea jump. The study used hedgehog fleas, but the other common fleas use the same technique. Most of the fleas in homes are cat fleas – a species that bites and feeds on people but which cannot breed on them.
The 3mm long bugs lay their oval shaped eggs on cat’s fur, but the eggs dry and fall out, usually on the blanket or carpet when the cat sleeps. The larvae hide from light and feed on dried cat blood. Once the adult has emerged from a cocoon, it jumps onto a host within seconds. The life cycle takes 30 days.
In 1967, Henry Bennet-Clark discovered that fleas store the energy needed to launch using a pad on their legs made of a stretchy substance called resilin. They take off at 3mph and reach speeds as high as 4.3mph.