Small localized lesions shall be placed in the anterior septal region, medial preoptic, hypothalamic nucleus, and lateral preoptic area and their effects noted on intermale conspecific aggression, cricket-killing, and the "rage" behaviors elicited by restraint and tactual stimulation of the dorsal cervical body surface. Additional control procedures will determine whether increases in behavioral baselines are induced by feric ion deposition, whether non-agonistic behaviors are affected, whether effects are mediated by olfactory reactivity to pheromones, and whether effects are reversible upon treatment with exogenous hormones.