Rodents have been studied extensively in the laboratory as model species to address and, in some cases, develop paradigms in mammalian behavioral biology. However, the laboratory environment presents obvious limitations that can compromise results, inferences, and application to evolutionary theory and the species’ natural history. Here I revisit several research areas that have been developed in the laboratory that either have never been tested in the field or, when they were tested, did not support laboratory results. Some of these studies include the Bruce effect, scent marking, mate choice, artificial selection, predator-induced reproductive suppression, and other behavioral anomalies. Whether laboratory results for these and other studies have produced facts or artifacts is equivocal, but they warrant critical evaluation. Rodents are excellent model systems for testing hypotheses in behavioral ecology. However, to improve our confidence in results from laboratory studies, the behavior being studied should be documented in the field, subjected to alternative hypothesis testing, applied to evolutionary theory and the species’ natural history, and field-validated.