Science and technology impact most aspects of modern daily life. It is therefore important to create a scientifically literate society. Since the majority of Americans do not take college-level science courses, strong K-12 science education is essential. At the K-5 level, however, many teachers lack the time, resources and background for effective science teaching. Elementary teachers and students may benefit from scientist-led outreach programs created by Cooperative Extension or other institutions. One example is the University of Arizona Insect Discovery Program, which provides short-duration programing that uses insects to support science content learning, teach critical thinking and spark interest in science. We conducted evaluations of the Insect Discovery programming to determine whether the activities offered were accomplishing program goals. Pre-post tests, post program questionnaires for teachers, and novel assessments of children’s drawings were used as assessment tools. Assessments were complicated by the short duration of the program interactions with the children as well as their limited literacy. In spite of these difficulties, results of the pre-post tests indicated a significant impact on content knowledge and critical thinking skills. Based on post-program teacher questionnaires, positive impacts on interest in science learning were noted as much as a month after the children participated in the program. New programming and resources developed to widen the potential for impact are also described.