With the global climate change, the ecology of the living and household environment has been severely disrupted. Neglectance and the inappropriate utilization of resources have resulted in nuisance in daily life and outbreak of serious vector-borne infectious diseases. Taiwan is located between the tropical and subtropical region. Thus, the warm and humid environment are ideal for the infestation of disease vectors including mosquitoes, flies, fleas, ticks, lice, cockroaches and mice. The vectors not only transmit the human diseases but also threaten the veterinary public health and animal industry by impairing the breeding of livestock and the production of animal products. On the other hand, some of the symbionts in the household environment played an important role on ecological decomposition or primary consumers but not trigger the disease. Sometimes it is vulnerable to misunderstand and lead to unnecessary anxiety in daily life. Through the introduction of a series of lectures, it will lead to the better understanding of these symbiotic organisms and their roles in the ecosystem, and even the application of such diverse resources. This course includes the lectures with specific topics, the practical observation of vector specimen, collection of the specimen in the field and the reading of supplementary literatures. Students are expected to understand the relationship between the pests or symbionts in the household environment and correlate to issues of public health.