Losing Your Head Over Love
Female praying mantises sometimes eat males during or after mating — but surprisingly, this only happens about 13-28% of the time in the wild.
The praying mantis has become famous for sexual cannibalism — females eating males during or after mating. But the reality is more nuanced than the legend suggests.
In laboratory conditions (where mantises are often stressed and hungry), cannibalism rates can be high. But in the wild, studies show females only eat their partners about 13-28% of the time. Most males mate successfully and escape.
When cannibalism does occur, it's not always bad for the male's reproductive success. If the female bites off the male's head during mating, his body often continues copulating — in fact, removing the brain removes inhibition, sometimes making sperm transfer more efficient. The male's body also provides nutrients that help the female produce more eggs, potentially including more of his own offspring.
Males aren't passive victims, either. They've evolved various strategies to avoid being eaten: approaching females when they're already eating, waiting until the female is sluggish, or performing elaborate courtship displays that may signal their quality as a mate (rather than a meal).
Sexual cannibalism has evolved independently in many species — spiders, scorpions, and other insects — suggesting it can be an advantageous strategy under certain conditions.