This one-day workshop brings together HCI researchers, designers, and practitioners to explore how to study and design (with) AI agents from a more-than-human design perspective. We invite participants to experiment with thing ethnography and material speculations, as a starting point to map and possibly integrate emergent frameworks and methodologies for more-than-human design. By using conversational agents as a case, participants will discuss what a more-than-human approach can offer to the understanding and design of AI systems, and how this aligns with third-wave HCI concerns of networks, infrastructures, and ecologies.