This article seeks to contribute to the idea of “posthumanist education” by unfolding an educational situation where an assemblage of two humans and 33 former battery hens is gathered to carry out a so-called cognitive bias experiment for two days. A Deleuzian repertoire is set in motion to configure the dynamics of hens intervening in the research schedule and affecting the results in various unexpected ways, as human-avian subjectivities co-emerge in the context of the fieldwork setting. The cognitive bias experiment ends in an ultimate line of flight; an act of animal liberation: The hens are moved from the research facility, where they were scheduled to be euthanized, to a private home in the countryside. Contained in the research process are two important messages to environmental educators: What are the implicit assumptions about nonhuman animals guiding environmental education practice and scholarship, and what are the connections between research and activism?