Animal models are a critical component of biomedical and biobehavioral research and have contributed to the exponential expansion of our understanding of human disease. Now, as we move onward into the era of genetics and genomics research, the importance of animal models to the research process will become even more acute as we explore the significance of genetic differences that are found in the presence and absence of disease. The decision to use an animal model is not one that can be taken lightly; but, rather, requires careful thought and consideration. In this review, we will address (a) why we should consider using animal models, (b) several caveats that are associated with using animals for research, and (c) some of the common genetic tools that are used in animal research.