Several studies have shown that starved females are more likely to cannibalize their mate than well fed females (Andrade, M.B. 1998). So when thinking about mating, the male has to use physical and chemical cues to determine the foraging abilities of the female. A recent study showed that this was the case in black widows. The researchers, from Arizona State University, found that males courted well-fed females significantly more than starved females. Interestingly, the researchers also found that males use chemical and physical cues to determine the female’s past foraging success, such as the quality of the female’s web. As such, even when the female spider was entirely absent from the picture, males spent more time courting the webs of well-fed females. Praying mantises have developed similar mechanisms through which males figure out ways to decrease the risk of their mortality by picking well fed females.





Hungry females are more likely to cannibalize
(Andrade, MB. 1998)




Mating ritual

To mate, the male must mount a female while pinning down her back and thorax with his forelegs. During this process, there are three opportunities for sexual cannibalism to happen -- before copulation, during copulation, and post copulation. In the pre-copulation stage, the female can decide to eat the male if she doesn’t perceive him as a suitable mate. Remarkably, females can also sever the male’s head during sex. The malecontinues to deposit sperm and sometimes even attempts an escape, despite the beheading. Finally, and most commonly, females cannibalize the male immediately after sperm deposition.




Check out this video for some great footage of sexual cannibalism in praying mantises!