Biologists produce knowledge that can be applied to both global and personal challenges. Thus, communicating this knowledge to the general public is becoming increasingly important. One way information can move between different communities is through boundary spanners. Boundary spanners are individuals embedded in both communities who can communicate information known by one community to the other. We explore whether undergraduate biology majors can act as boundary spanners connecting their biology departments to laypeople in their personal networks. We conducted 20 interviews with upper-division first-generation college students at a large Hispanic-serving institution. These students were engaging in everyday conversations about science with people in their personal networks. They engaged in behaviors that characterize boundary spanners: translating scientific language into more common language and knowledge building, that is, providing background concepts that community members need to understand a topic. Finally, students were sometimes perceived as credible resources and sometimes were not. We explore some of the causes of this variation. The boundary spanning of undergraduates could help address one of the major challenges facing the scientific community: spreading the use of scientific knowledge in personal and policy decision making.