Yarkon stream, Israel
This bulbous creature is a spring tail, a bug that’s actually not considered an insect because it has internal mouth parts, as opposed to insects who all have external mouth parts. At barely 1.5 mm long, it was actually very large compared to its yellow cousins who measured just 1 mm.
Most species of spring tail have an abdominal, tail-like appendage, the furcula, that is folded beneath the body to be used for jumping when the animal is threatened. It is held under tension by a small structure called the retinaculum and when released, snaps against the substrate, flinging the spring tail into the air. All of this takes place in as little as 18 milliseconds. In this image, the furcula can be seen tucked beneath the body, between the legs.