Fear of mice and rats is one of the most common specific phobias. It is sometimes referred to as musophobia (from Greek μῦς "mouse") or murophobia (a coinage from the taxonomic adjective "murine" for the family Muridae that encompasses mice and rats), or as suriphobia, from French souris, "mouse".

The phobia, as an unreasonable and disproportionate fear, is distinct from reasonable concern about rats and mice contaminating food supplies, which may potentially be universal to all times, places, and cultures where stored grain attracts rodents, which then consume or contaminate the food supply.

In many cases a phobic fear of mice is a socially induced conditioned response, combined with the startle response common in many animals, including humans, rather than a real disorder. At the same time, as is common with specific phobias, an occasional fright may give rise to abnormal anxiety that requires treatment.

Fear of mice may be treated by any standard treatment for specific phobias. The standard treatment of animal phobia is systematic desensitization, and this can be done in the consulting room (in vivo), or in hypnosis (in vitro). Some clinicians use a combination of both in vivo and in vitro desensitization during treatment. It is also helpful to encourage patients to experience some positive associations with mice: thus, the feared stimulus is paired with the positive rather than being continuously reinforced by the negative.

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