This paper examines the potential of posthumanism to enable a reconceptualisation of young children's literacies from the starting point of movement and sound in the more-than-human world. We propose movement as a communicative practice that always occurs as a more complex entanglement of relations within more-than-human worlds. Through our analysis, an understanding of sound emerged as a more-than-human practice that encompasses children's linguistic and non-linguistic utterances, and which occurs through, with, alongside movement. This paper draws on data from two different research studies: in the first study, two-year-old children in the UK banged on drums and marched in a museum. In the second study, two young children in Australia chose sites for their own research and produced a range of emergent literacies from vocalisation and ongoing stories to installations. We present examples of ways in which speaking, gesturing and sounding, as emergent literacy practices, were not so much about transmitting information or intentionally designed signs, but about embodied and sensory experiences in which communication about and in place occurred through the body being and moving in place. This paper contributes to the field of posthuman early childhood literacies by foregrounding movement within in-the-moment becoming. Movement and sound exist beyond the parameters of human perception, within a flat ontology in which humans are decentred and everything exists on the same plane, in constant motion. Starting from movement in order to conceptualise literacy offers, therefore, an expanded field of inquiry into early childhood literacy. In the multimodal literacy practices analysed in this paper, meaning and world emerge simultaneously, offering new forms of literacy and representation and suggesting possibilities for defining or conceptualising literacy in ways that resist anthropocentric or logocentric framings.