Multicellular biofilms constructed by microbes are key aspects of microbiology with significant implications in various fields, including medicine, environmental science, and biotechnology. While bacteria spend nearly all their lives in biofilms, many students do not study them in detail in a course setting. Consequentially, students have misperceptions that microbes exist as free-living single-cell organisms and cannot understand the biofilm lifestyle accurately. Here, I present a comprehensive and engaging lab lesson plan designed for students to explore the concepts of biofilm lifestyle and compare biofilms to cities using a think-group-share strategy. Students are asked to individually define biofilms and relate them to living in a city, followed by forming small groups, and then discussing them as an entire class. The class will understand the different aspects of biofilms in each step of the life cycle from colonization to dispersal. Subsequently, the students will put their knowledge into practice by completing an activity where they must sort different functional activities into the following steps in the biofilm life cycle: colonization, formation, maturation, and dispersal. This analogy-based activity encourages comparative analysis and fosters long-term learning. I observed that students actively participated in the learning activity, which also cultivated a sense of class community during the sharing session. An end-of-module review activity six weeks later showed that the students could still recall the knowledge learned during the lesson. This lesson activity has several advantages: it is easy for the teacher to implement within 20–30 minutes and convenient for the students to engage with biofilm biology.

Primary Image: Comparison of a biofilm to a city. The biofilm has similar analogies to a city.