In this paper we present an initial study of how metaphors are used by university-level Computer Science instructors. The goal of this research is to gain a better understanding of the role that metaphors play in Computer Science education, to catalog the kinds of metaphors that are used, and to assess their effectiveness in supporting learning. We interviewed 10 educators in Computer Science about the metaphors they have used in the classroom, with a focus on introductory "CS1" programming courses. We analyze these interviews with an existing theory of metaphors, which provides a framework for describing their structure and features. The theory predicts that most metaphors have limitations, and eventually fall apart. Therefore, we also asked educators to assess how far they could push their metaphors with and to describe what happens at the breaking point. Our preliminary findings provide a foundation to inform and guide more in-depth analyses in the future.