Based on recent ethnographic fieldwork at an intensive dairy farm, this chapter examines the usefulness of posthuman critical theory for developing a new sociolinguistic approach to nonhuman animal agency. We explore how dairy cows, as encaged sentient beings whose mobility is profoundly restricted by bars and fences, negotiate their environment as a material-semiotic resource in linguistic acts of place-making. Drawing on the fields of critical posthumanism, new materialism and sociolinguistics, we explain how dairy cows imbue their physical space with meaning through materiality, the body and language. By developing a non-anthropocentric approach to language as a practice of more-than-human sociality, we argue for establishing egalitarian research perspectives beyond the assumptions of human exceptionalism and species hierarchy. The chapter thus aims to contribute towards a new understanding of nonhuman agency and interspecies relationships in the Anthropocene.