Cercus

However, it is not always obvious that small cerci are without function; they are rich in sensory cells and may be of importance in guiding copulation and oviposition.

In field crickets, the range of frequency detection by the cerci spans from infrasonic sound to nearly 1 kHz.

In crickets, higher-frequency sound such as stridulation and ultrasonic bat calls are picked up by a separate tympanal organ, not the cerci.

[4] Some hexapods such as mayflies, silverfish and diplurans possess an accompanying third central tail filament which extends from the tip of the abdomen.

Like many insect body parts, including mandibles, antennae and stylets, cerci are thought to have evolved from what were legs on the primal insect form,[3] a creature that may have resembled a velvet worm, Symphylan or a centipede, worm-like with one pair of limbs for each segment behind the head or anterior tagma.