From Biology News Net:
Female praying mantids are notorious for sexual cannibalism – that is, for eating their male partner during mating.
However, the possibility that males may also have something to gain from this violent act has never been resolved experimentally.
In a paper in the August issue of The American Naturalist, Jonathan Lelito and William Brown (SUNY-Fredonia), study male risk-taking behavior in a praying mantis by altering the risk of cannibalism and observing changes in male behavior.
They find that the males are able to assess the risk of cannibalism and become more cautious in the presence of particularly hungry females.