Notes & TheoriesAnimal behaviourJumping fleas reveal their secrets to Cambridge scientists
High-speed video shows that jumping fleas take off from their toes rather than their knees, as other researchers had suggestedThe secret of the flea's incredible jumping skills has been laid bare by Cambridge researchers who used high-speed video to capture the insects in the act of take-off.
The footage shows that the animals catapult themselves into the air by releasing energy stored in the thorax through their leg segments, which in turn push down on their toes.
This explosive release of energy propels the fleas upwards at speeds of as much as 1.9 metres per second (4.25 miles per hour). Fleas, which weigh less than a gram, can jump around 30cm high.
Scientists have debated the finer details of the flea leap since 1967 when Henry Bennet-Clark, a zoologist at Oxford University, discovered that the animals jump by releasing energy stored in a pad made of an elastic protein called resilin.
When the Cambridge biologists Malcolm Burrows and Gregory Sutton came by a supply of hedgehog fleas, they decided to study the animals' aerial feats.
"We had a serendipitous set of hedgehog fleas show up so we figured we'd take a crack at it and try to answer the question," Sutton said.
Evidence from footage of 51 jumps taken by 10 fleas showed that they took off from their toes, rather than their knees, as some previous researchers had suggested.
The research appears in the Journal of Experimental Biology.
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