Scientists have discovered a hermaphrodite flatworm that literally fucks itself in the head. The flatworm resorts to self-insemination when it’s unable to find a mate. How's that for kinky? The flatworm, Macrostomum hystrix, is able to use this reproductive strategy as they have both male and female sex organs. Though this produces ‘inbred’ offspring, it’s still better than not being able to reproduce at all, researchers suggest.