Springtails are wingless and do not fly but they can jump, using a specialized forked appendage called a furcula, located underneath the abdomen at the posterior end of the animal.
Not all species of springtails have a furcular. For example, springtails that live deeper in the soil usually do not have the appendage because jumping is not a practical means for escape.
Between jumps, the furcula is held within a ventral groove in the springtail’s abdomen.
When it is time to jump, the springtail’s furcula moves from its retracted position to an extended position.
After it passes a critical point of extension, an internal “spring” releases all the energy, which in turn causes the furcula to snap out at high speed.
If the furcular strikes a hard surface, a force is created that propels the springtail.
Many researchers find the springtails’ jumping mechanism particularly intriguing because it is very efficient at a very small scale.