How can we make sense of the fact that we live in a world where good people co-exist in silence about widespread animal suffering. How is it that sites of suffering such as laboratories, factory farms, abattoirs and animal transportation are all around us and yet we ‘do not, in a certain sense, know about them’ . This ‘not knowing’ is one of the most difficult barriers for animal activists who must constantly develop new strategies in an attempt to catch public attention and translate it into action. Recent contributions from the ‘sociology of denial’ have elucidated many of the mechanisms involved in ‘not knowing’ in relation to human atrocities and genocide. In this context, ‘denial’ refers to the maintenance of social worlds in which an undesirable situation is unrecognized, ignored or made to seem normal . These include different types of denial: personal, official and cultural, as well as the process of normalization whereby suffering becomes invisible through routinization, tolerance, accommodation, collusion and cover up. Denial and normalization reflect both personal and collective states where suffering is not acknowledged . In this paper, I will examine insights from the sociology of denial and apply them to human denial and normalization of animal suffering. This will include an examination of denial which is both individual and social and the implications of these insights for theory and practice in the human/animal relationship.