Furcula (springtail)

[1] While at rest, it is retracted under the abdomen and held there by a structure variously called the retinaculum or hamula,[2] which in turn is located beneath the third abdominal segment.

Furthermore, the furcula is effective in environments typical of Collembola; most predators of springtails are small and many have little power of sight, so if the prey leaps in time, the chances are that from the hunter's point of view, it simply vanishes.

The absence of a furcula in such species commonly is explained as an adaptation to a way of life in which a jumping or flying organ might get the animals into trouble more often than it rescues them.

During the jumps, some species can perform several tumbles making their orientation unpredictable at the time of landing, after which they have the ability to recover very quickly.

In aquatic species, the mucron is often wider, more flattened in shape like a paddle, which allows it during jumps to be supported on the liquid without breaking the surface tension.