The pain analysis can be done from different perspectives, depending on the theorical basis for this study. The present paper is based on the behavioral analytic perspective, understanding pains as a covert behavior. We analyze some animal studies demonstrating that pain can be a function ontogenetic processes (operant or respondent learning) moreover the phylogenetics ones. We conclude that it is necessary more interaction among the different sciences interested on the pain study, like the Physiology, Pharmacology or Behavior Analysis.