Interactive art is evolving toward a more-than-human perspective, embracing the significance and opportunities of involving nonhuman participants. This raises questions about the forms and types of interactions applied in such artworks. To capture and analyze interactions facilitated by interspecies artworks, the authors apply a relational model that they originally developed for describing human co-located interaction. By uncovering patterns in the roles of human and nonhuman elements within these artworks, the authors demonstrate that the relational model is effective not only in analyzing such interactions but also in proposing novel roles for future more-than-human interactive art.