The goal of this chapter is to describe the general strategies scientists use to measure behavior in rodents, invertebrates, and primates. First, we will discuss some of the issues a scientist must consider when choosing and performing behavioral assays. Then we will survey the behavioral assays that are the most commonly used in the literature. This will not be a comprehensive overview, but a flavor of the methods used to elucidate the neural basis of behavior. You will learn how to compare and contrast the advantages and disadvantages of common model organisms used to study animal behavior, discuss considerations for designing a behavioral assay, and describe common behavioral assays used in rodents, invertebrates, and primates.