The flea's appearance under the microscope is so unusual as to appear diabolic, and diabolic is its ability to escape capture with a leap so swift that it abruptly eludes the eye and seems to disappear. It is precisely this leap that [is] rich in patience and ingenuity... [The flea's] elastically deformable musculature is analogous to a gun's spring and a crossbow's arch. [It] is constituted of a protein...almost unique in the animal kingdom, similar to rubber but with properties that have a much higher degree of performance. In this way the energy required for the instantaneous and prodigious leap is accumulated during a slower preparatory phase: between one leap and the next, the flea must "collect itself," again accumulate energy for its springs; but even for these pauses it needs only a tenth of a second. And this is the secret which allows the insect to leap even in cold environments, and leap so high and so far.