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When does tonic immobility usually begin during an attack by a predator?
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Avoidance behaviour
Cat fleeing by upward climbing.
In the context of predator-prey interactions, tonic immobility is typically initiated when a predator has already caught or is holding its prey. While a freezing response occurs earlierātriggered as soon as an animal detects a predator to avoid being seenātonic immobility serves as a final, basal defense mechanism used after the prey has been captured.1
However, there are exceptions to this timing. In some instances, the state may be triggered simply by the proximity of a predator, and certain species, such as the Virginia opossum, are capable of initiating this response even before physical contact occurs.1