The Open Field Test (OFT) evaluates animals’ behavioral responses when placed in an unfamiliar environment. The test measures individual differences in exploratory behavior, activity levels, and responses to social contagion and novelty. This test can be performed in different environments and can be designed to test a single animal or multiple animals in one testing session. It is adaptable to all age classes. The test procedure described in this SOP is performed in an open field arena on two or more animals.