Class discussion can be a valuable way to meet educational standards and make student ideas visible. Tools like Twitter can be used to encourage discussion both in and outside of class. In this article, we provide (1) a concise explanation of Twitter and its use (including a comparison to similar digital communication tools); (2) a brief overview of educational gains and experiences in using Twitter; and (3) a step-by-step introduction to conducting Twitter discussions using hashtags. We conclude with an introduction to #scistuchat, a monthly Twitter discussion between scientists and students that addresses many of the core ideas in the biological sciences. We invite instructors to join this ongoing discussion series or use the ideas within this paper to begin their own discussion groups on social media.