Dear Pam,
From a behavior management point of view, I would continue to set limits on the behavior, as you have been doing. I'd also arrange an appointment with his pediatrician, both to have him examined and to have the pediatrician talk with your son about the risks of such behavior (relative to causing an injury or irritation).
Beyond this, it would be sensible to have an evaluation with a
mentalMental retardation
Mental status tests health professional, at the very least to assess this situation and to take a look at your son's overall
psychologicalChild neglect and psychological abuse development.