Calls for improvement of undergraduate science education have resulted in numerous initiatives that seek to improve student learning outcomes by promoting changes in faculty teaching practices. Although many of these initiatives focus on individual faculty, researchers consider the academic department to be a highly productive focus for creating change. In this paper, we argue that it is important for change agents to understand the informal social structure of the academic department and introduce social network analysis techniques to uncover this social structure. Examples are given from data collected in five academic departments. A short sociometric web survey was used to ask instructors to identify colleagues with whom they discuss teaching and the frequency of their discussions. Techniques of social network analysis are used to determine the current state of the department, target participants for a change initiative, and anticipate the spread of new teaching ideas. Results suggest that these techniques identify informal structures that would otherwise be hidden and that may be important for planning change initiatives.