The recent more-than-human turn has increased interest in writing about relations between humans and other animals. In addition, scholars have called for a need to complement the animal turn with a turn to microbes. Microbes entangle all life in relations and participate in processes of living and dying, but thus far, they have been largely absent in environmental education research. This article attempts to think with microbes in environmental education by zooming into the phenomenon of 'moldschools' in Finland. Employing the concept of agencement, the article first explores how school buildings, toxic molds, and humans have effectuated each other and introduces the idea of indoor climate crisis. Then the article explores the complexity of everyday life in one moldschool, asking, how was the school becoming felt and practiced differently by children and teachers in relation to material-discursive mold. Finally, the article asks what moldschools might teach us or ask from us in terms of environmental education and ethics. The notion of schools as always already more-than-human agencements is offered to make space for hesitation and curiosity on various scales of connection.