We share insights from a project with middle and high school environmental science teachers in Baltimore, MD, focused on responsive teaching. How do teachers modify their curriculum and teaching in response to student thinking? To what do teachers attend, in terms of student thinking, in environmental science classrooms? What professional development strategies foster greater and more productive attention? Notes and video from classroom observations and regular follow-up conversations with teachers, transcripts of these meetings, reflections written by teachers, and artifacts from teachers’ classrooms comprise the data for this study. Preliminary results were rather stark: we saw very little evidence of careful attention to student thinking and few examples of responsive modifications. Most responses simply sought to correct “incorrect” statements by students. Our evidence suggests that too much focus on the correctness of ideas actually may detract attention from substance and the nature of student reasoning which, if listened to, could be tapped and built upon. Our study demonstrates a useful approach to describing teacher attention to student thinking; the combination of videotaping classroom practice and reflecting on these episodes with peers and education researchers is yielding a useful framework for responsive teaching. Furthermore, we are learning ways in which these same research approaches can foster increases and shifts in teacher attention to student thinking in biology and environmental science, at least among a subset of our teacher participants. Teachers’ commitment to a broader set of student outcomes than just scientific understanding (e.g., student agency in solving environmental problems) can lead to less attentiveness to student thinking about science. However, it also can lead to teachers recognizing productive prior knowledge about the environment among their students, and to instructional steps that use this as a foundation for student growth in both science and agency for problem solving.