This course examines the chemical basis of naturally occurring ecological interactions. It will focus of chemical signals of plants, animals and microbes in diverse ecosystems. The course will aim to teach sample collection, preparation and chemical analysis using gas chromatography-mass spectrometry and other mass spectrometry based techniques. Expected outcome of the course include familiarity with general organic molecules, their structure and relationship to function. Students will be able to understand and use analytical techniques used for analysis of chemical compounds that mediate ecological interactions. Further, the course will enable students to read and synthesize scientific research in chemical ecology by discussion of literature.