Abstract: Feminist science studies have given scant regard to non-human animals. In this paper, we argue that it is important for feminist theory to address the complex relationships between humans and other animals, and the implications of these for feminism. We use the notion of performativity, particularly as it has been developed by Karen Barad, to explore the intersections of feminism and studies of the human/animal relationship. Performativity, we argue, helps to challenge the persistent dichotomy between human/culture and animals/nature. It emphasizes, moreover, how animality is a doing or becoming, not an essence; so, performativity allows us to think about the complexity of human/animal interrelating as a kind of choreography, a co-creation of behaviour. We illustrate the discussion using the example of the laboratory rat, who can be thought of both in terms of a materialization of specific scientific practices and as active participants in the creation of their own meaning, alongside the human participants in science. There are three, intertwined, senses in which we might think about performativity – that of animality, of humannness, and of the relationship between the two. Bringing animals into discussions about performativity poses questions for both feminist theory and for the study of human/animal relationships, we argue: both human and animal can conjointly be engaged in reconfiguring the world, and our theorizing must reflect that complexity. We are all matter, and we all matter.