Socio-scientific issues and socially acute questions enable moral judgement through rational, emotional, intuitive and imaginative thinkings. Our research focuses more specifically on the place of the myth in student discussions about controversial issues. We have analysed the mythemes expressed through online exchanges between students from England, France and New Zealand about three 'pest'-animal issues, the 'pests' in question being the Badger (England), Wolf (France) and Possum (New Zealand). We observe the expression of recurrent mythemes by issue, one demonizing the animal and encouraging its destruction or control, one protecting its proper nature, one ambivalent proposing a dialogue between the two first ones. These expressions relate to the living socio-cultural contexts of the students. The mytheme expressed by each student remains stable during the discussion. The potential of myths to enable critical thinking in intercultural communication is discussed.