Praying mantises are known to devour their mates after having enjoyed the poor males’ sexual prowess .This behavior is not unique in nature: female spiders are also known to feast on their sexual partners especially when the males are smaller than the female  and now scientists have discovered a similar behavior in female rattlesnakes  shortly after giving birth, apparently out of a need to replenish her energy and become reproductive again.
Are the males of the animal kingdom always the victims of their mates? Not quite, according to research published in the very learned American Naturalist ,certain male fishes become cannibals when they suspect they have been cuckolded and the off springs are not really theirs.
Assuredly, no one could find parallels between the human and animal behaviors!
 cf. University of Chicago Press Journals. "Male Praying Mantids Prefer Not To Be Victims Of Sexual Cannibalism." ScienceDaily 27 July 2006. 22 February 2009 <http://www.sciencedaily.com/releases/2006/07/060726183753.htm#>.
 University of Chicago Press Journals. "Female Spiders Eat Small Males When They Mate." ScienceDaily 11 September 2008. 22 February 2009 <http://www.sciencedaily.com/releases/2008/09/080910165846.htm>.
 Plataforma SINC. "Cannibalism Among Rattlesnakes Helps Females To Recover After Birth." ScienceDaily 22 February 2009. 22 February 2009 <http://www.sciencedaily.com/releases/2009/02/090219095533.htm>.
 Suzanne M. Gray, Lawrence M. Dill, and Jeffrey S. McKinnon, "Cuckoldry incites cannibalism: male fish turn to cannibalism when perceived certainty of paternity decreases." The American Naturalist: February 2007.