Men are able to detect a woman when she is at her most fertile stage just by watching the way she walks, according to a new study.
While dance moves are also a giveaway, researchers said that the way a woman walks is the biggest clue into her fertility.
German researchers are unsure what signal women give at the peak of their fertility, but they believe that it may involve the sway of her hips.
Researchers from the University of Gottingen shot digital videos of 48 women between the ages of 19 and 33 years walking up and down in a straight line and dancing for 30 second bursts.
Researchers then turned their movements into silhouettes so that their appearance did not diminish the effect of their moves.
Scientists had filmed each female participant twice, once when they were at their most fertile period, and again when their odds of getting pregnant were very low.
Afterwards, 200 men were asked to watch the videos of the silhouette and rate how attractive the moves were.
The results show that both the dances and walks recorded at the women's most fertile period was significantly more attractive compared to movements recorded in the women's least fertile stage, according to the study published in the journal Personality and Individual Differences.
While the scientists didn't dissect the women's movements to find out just what was attractive to the male eye, lead researcher Bernhard Fink believes that the association does not involve the speed of the women's walk, but instead is linked to the sway or the wiggle in their hips.
Researchers concluded that the study suggests that women's body movements provide subtle clues to female fertility which men can detect and are attracted to.
In a 2010 study, Fink asked females to rate male dance movements and found that women were most attracted to men who varied both their moves and the scale of their moves.
Researchers say that the study may suggest that the variation in moves and the scales of the moves may indicate a creative personality and a strong, healthy and flexible body, characteristics that are important when selecting a mate.
However, researchers found that with the exception of the right knee, exaggerated movements from the arms and legs did not attract women.
Last month, Belgium researchers, writing in The Journal of Sexual Medicine, found that a woman's walk also revealed intimate details of her sex life like whether she regularly had orgasms from penile intercourse.