Fieldwork in ecology education does things. By employing Donna Haraway's concept "becoming-with companion species" and Cathrine Hasse's "emotional collectives" to explore fieldwork practice on a bog in Sweden, a piece of the doings will be told. The aim of this study is to explore how ecology fieldwork affords emotional engagement and facilitates growth of ecological literacy in the emotional collectives of students, teachers and nonhumans to become-with each other. The study is based on an overnight field trip with upper-secondary students experiencing black grouse lekking and the ecology of a bog. The empirical material consists of video and audio recordings. In the study, becoming-with is operationalised through the notion of emotional collectives. The result shows three orientations of becoming-with: "mimetic," "anthropomorphic" and "fact oriented." Overall, this is a story of fieldwork as a practice of producing companion species; how becoming-with companion species works in practice, how companion species come to matter as emergent ecological literacy.