Yale: Female Ducks Say No to Sex

Females have for centuries found creative ways to fend off unwanted advances from men, but few have gone to the same lengths as these female ducks being studied by Yale. These women are so put off by pushy males, they've actually evolved genitalia designed to sabotage any man's physical advance.

Basically the female duck's secret place is in a spiraling shape that is very difficult for the male duck to navigate with his equipment. This gives the female more power to decide when she will let a male get what he wants. In fact, the scientists say that male and female ducks have been in a sexual arms race of evolving anatomy! For the full rundown see the link below.

Yale: Female Ducks Say No to Sex
eurekalert

Scientists at Yale University in New Haven, Connecticut, have explained the mechanism by which female ducks thwart forced copulations.

Lady ducks have evolved a unique way of avoiding the unwanted advances of, er, enthusiastic suitors, according to Yale scientists. According to researchers, while male ducks have developed longer, spiraled genitalia, the females' anatomy has evolved to spiral in the opposite direction. "In species where forced copulation is common ... this coevolution results from conflict between the sexes over who is going to control fertilization," said Yale researcher Patricia L.R. Brennan...

Yale: Female Ducks Say No to Sex