It also resulted that the male version of the paragenitalia was more effective, as these females presented less scarring due to penetration than other females.

This is a "a spectacular example of evolution through sexual conflict," said Reinhardt to New Scientist.

"Males started getting nobbled by other males, so they evolved the female defensive genitalia. As this reduced the amount of penis damage they were getting, females evolved the male version of the male genitals." he added.

Bat bugs are parasites feeding on the blood of the bats, and in their absence they can also attack people. A close relative and more known is the infamous bed bug.