Sexual cannibalism, the process by which some female creatures eat their male counterparts after mating, seems quite unpleasant but has been noted at least 30 species, including those in three orders of insects and in orders of arachnids, amphipods, copepods, and gastropods. Under certain conditions, it's theoretically evolutionarily beneficial for the male to sacrifice himself for the good of his offspring. But recent research is showing sexual cannibalism may be the exception, rather than the rule, even in certain species long thought famous for it. Some species of insects, like the male praying mantis, are a bit more willing to do whatever it takes to achieve this goal. At least in captivity and in environments where the female is concerned about limited nutritional resources, the male is sacrificed.