Defensive attack behavior in male and female rats

Male rats in a restraining tube bit and wounded the snout of an anesthetized male conspecific as a direct function of the intensity of tailshock, with bites declining systematically in the time interval after shock. Female rats’ bites on a male rat were also dependent on shock, but did not produce wounds. When an anesthetized cat was presented to rats in the same situation, females bit and wounded the cat before shock was given, while the males again bit only in response to shock. These data were interpreted as indicating that male bites on both a conspecific and a predator fit the same defensive biting pattern. In contrast, females’ bites on a male rat are actively inhibited, while females’ bites on a predator are neither inhibited nor shock dependent: this latter finding may reflect the adaptive value (protection of the young) of attacking a predator before it hurts the female rat.