Thanatosis
Thanatosis is a defensive behavior in which an animal becomes motionless or appears dead. It can reduce attack by predators or help capture prey.
Tonic immobility: A temporary state of reduced movement that can follow restraint, threat, or intense stimulation. Thanatosis is often described as tonic immobility when an animal remains still after a predator seizes it.
Predator avoidance: Behaviors and traits that reduce the likelihood of being detected, attacked, or eaten by predators. Thanatosis is one way prey animals can disrupt a predator's attack or lose its interest.
Freezing behavior: A defensive response in which an animal becomes still when it detects a threat. Freezing often begins before contact, while thanatosis commonly follows close approach or capture.
Predation risk: The probability that an organism will be attacked or killed by a predator. Thanatosis is expected to vary with the kind of predator and the danger an animal faces.
Thanatosis in opossums: A defensive response in which an opossum lies limp and may produce saliva and anal secretions. The opossum is a well-known example of a mammal whose apparent death can deter predators.
Playing possum: An idiom based on an opossum's defensive display of apparent death. The familiar phrase comes from a real form of thanatosis, though the animal's response is involuntary.
Death feigning: A defensive display in which an animal behaves as if dead to influence another animal's behavior. This near-synonym emphasizes the apparent-death display, while thanatosis can also describe the underlying immobility.
Antipredator behavior: An action that reduces an animal's risk of being detected, attacked, or consumed by a predator. Studies place thanatosis among diverse behaviors whose effectiveness depends on ecological context.
Thanatosis in beetles: A defensive response in which a beetle folds its appendages and remains motionless when disturbed. Many beetles use immobility and a tucked posture to become less noticeable or less appealing to attackers.
Sexual cannibalism: The consumption of one mating partner by the other, usually the female consuming the male. Male nursery-web spiders may feign death during courtship, a behavior associated with avoiding cannibalism and increasing mating chances.