Several types of insects have a body part called a cercus (plural cerci) which usually comes in a pair. Insects with these features typically have their cerci located at the end of their abdomen. The best examples of such insects are crickets and earwigs. The crickets’ cerci are straight, whereas those of the earwigs are curved and pincer-shaped.
Cerci are sensory structures as are an insect’s antennae. They often tend to be larger in males. Cerci could serve little or no function for some insects. However, some use them as pinching weapons.