How do active avoidance and passive avoidance differ in animals?

In the study of avoidance behaviour, animals exhibit defensive responses to adverse stimuli that differ primarily in the nature of the motor response and the opportunity to escape.

Active Avoidance

Active avoidance is characterized by the animal’s opportunity to flee or perform a specific action to escape a threat. In laboratory settings, this often involves the animal learning to perform a task—such as running away or turning a paddle wheel—to terminate a warning signal or avoid a painful stimulus like an electric shock. This behavior is often coordinated by specific sites in the brain, such as the hypothalamic and mesencephalic zones.123

Passive Avoidance

Passive avoidance involves the inhibition of a previously exhibited response. Rather than fleeing, the animal remains still, often freezing or hiding, when a stimulus associated with punishment is present. This freezing response entails general motor inhibition and can sometimes lead to reduced arousal or states of immobility. Passive avoidance is particularly likely to occur when the threatening stimulus is difficult to locate or when there appears to be no viable path for escape.12