Background: The goals of laboratory experiences include developing knowledge base, research skills, and scientific communication abilities. Objective: The aim was to assess an inquiry-based laboratory activity using the model organism "Caenorhabditis elegans" in relation to learning goals. Method: Students in a "Biopsychology" laboratory course worked in groups to test the effect of various drugs (e.g., nicotine, ethanol, fluoxetine, and melatonin) on "C. elegans" behavior. The activity included literature review, experimental design, and a final lab report. A cumulative final exam included a synaptic communication question related to the content of the activity. Results: Students showed better retention of laboratory-related content compared to other topics from the course, as demonstrated through performance on the final exam and were able to replicate previous research demonstrating effects of drug on locomotion. However, students did not improve writing ability compared to performance on a previous American Psychological Association style lab report. Conclusion: This study demonstrates that using a student-designed, multi-week laboratory assignment in an undergraduate Biopsychology course supports the growth of psychology knowledge and the development of research skills. Teaching Implications: Instructors should consider using the described laboratory activity for biopsychology or behavioral neuroscience classes or consider similarly designed laboratory formats for other courses in Psychology.