Nature is never a good place to look for moral guidance. Anything goes, as long as it increases the chances of one's genes being passed down the generations. Take the male Amazonian frog Rhinella proboscidea - it doesn't even care whether its mates are alive or dead. Males gather in huge numbers at spawning sites during the brief, desperate mating season, battling among themselves for access to females. It's the only known example of necrophilia having an evolutionary advantage - to both the male and the unfortunate female, who would otherwise have missed out on breeding entirelyDiscover more fascinating frog facts