Action research was conducted in two sections of a scientific inquiry class in a Midwestern U.S. university to identify the types of questions that students ask for their investigations, identify emerging patterns regarding students' questioning, and determine students' ability to transfer their nature of science (NOS) understanding to a new scientific phenomenon. Participants included 28 non-science major freshmen and sophomores. Data sources included the Earthworm Activity Field Guide, the post-reflection sheet, The Views of Nature of Science Version B Questionnaire (VNOS-B), and audio recordings of small group discussions when students were creating and selecting questions for the first and the second investigations when they were in the field. Findings showed that students improved their ability to ask more investigable and more specific questions after conducting an investigation. Also, students asked fewer descriptive and more cause-and-effect or pattern-seeking questions after the first investigation. The results showed that students were able to apply their understandings of NOS aspects to a new concept. However, some aspects were addressed more than the others. Results suggest that giving students opportunities to ask their own questions following their own interests improves their ability to generate good investigable questions. The results also suggest that reflecting on NOS aspects during content-related inquiry activities enhances students' NOS understandings.