Neuroscientists uncover sensory switches controlling infanticide and parental behavior
(PHYSorg.com Biology)

Many species of mammals have evolved what appear to be paradoxical behaviours towards their young. Like humans, most exhibit nurturing, protective behaviours, and in some circumstances even act as surrogate parents. However, virgin males often engage in infanticide as a strategy to propagate their own genes. How are these conflicting social behaviours controlled?