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Rodent grooming behavior, besides other biological functions (e.g., cleaning and thermoregulation), can be elicited by arousing experiences. Accordingly, it has been suggested in studies involving anxiety or stress that grooming provides useful information. Different situations are expected to involve diverse behavioral processes. Taking this into account, to evaluate how grooming measures could reflect these processes, in the present work, we studied the behavior of 40 rats in 30-min sessions in the following behavioral tests: elevated plus maze, marble-burying test, operant extinction, exposure to a conditioned-fear context, and exposure to novelty after restraint stress. While rostral grooming prevailed over body grooming in the beginning of the session in all tests, the latter prevailed after 10 min only in the elevated plus maze and the marble-burying tests. As these tests seem to involve transitory arousal, the late increase and prevalence of body grooming may correspond to a de-arousal process. Stereotyped grooming chains seemed to indicate recovery from high levels of arousal. Indeed, chain frequencies were higher in the beginning of each test (i.e., before adaptation to the test condition) than later in the session. Further, they were higher immediately after a restraint period than in any other test. The gross measure of "grooming duration" was not sensitive enough to reflect all the effects found in the detailed recording. Furthermore, compared with 5-min recordings, 30-min sessions allowed grooming data to be more heuristic. We conclude that the usefulness of grooming in neurobehavioral research is potentially greater than its present uses reflect.

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