From Environmental Graffiti:
Imagine every time you made love to your partner you were dicing with imminent death. It might make you wary of having sex ever again (if you survived, that is!) yet male praying mantises can never be sure they will survive the sex act. Sexual cannibalism is a natural phenomenon whereby one organism (generally the female) eats the other (typically the male) before, during or right after sex. This amazing sequence of photographs shows a female praying mantis eating her lover – starting with this shot of Mrs Mantis munching on the male's leg. Looks like a nice appetizer!
What's crazy about the whole eating-her-partner aspect of preying mantis sex is that the act of eating him can actually makes him a better sex partner, at least from a reproductive point of view:
Once the head is bitten off, the male's movements become more active and energetic. This results in a more vigorous and, one would surmise, more abundant and perhaps deeper delivery of sperm.
See the other 9 spectacular photos of the female mantis gobbling her partner here.
And of course, what would this post be without some gratuitous mantis cannibalism porn: