Possums exhibit a unique defense mechanism known as thanatosis, or “playing dead.” This behavior is an involuntary physiological response to extreme stress or perceived threats. It serves as a last-resort strategy for survival when a possum feels it cannot escape danger.
The Physiology of Playing Dead
When a possum enters this state, its body undergoes a transformation designed to mimic death. The animal typically collapses onto its side, becoming motionless and rigid, with tensed muscles. Its eyes may remain open but appear glazed, while its mouth hangs open, often with frothy saliva and a blue-tinged tongue. Breathing becomes shallow and infrequent, and the heart rate slows significantly, making it difficult to detect signs of life. To enhance the illusion, the possum may involuntarily discharge urine and feces, and release a foul-smelling, greenish fluid from its anal glands, creating an odor of decay.
This state is an automatic reflex triggered by the nervous system in response to an overwhelming threat, similar to fainting in humans. Despite appearing deceased, the possum remains alive and aware of its surroundings, monitoring for the danger to pass. This “tonic immobility” differs from simply freezing, where an animal is poised to flee; in thanatosis, the possum’s body cannot move.
How Long Does It Last?
The duration of this death-feigning state can vary considerably, typically lasting from a few minutes to several hours. While some possums may recover within a minute or two, others can remain in this state for up to four hours, or even longer. The length of time a possum stays “playing dead” is influenced by the intensity of the perceived threat and the presence of predators.
The possum will only emerge from thanatosis once it senses the danger has passed. It cannot be coaxed or prodded out of this state, as the response is involuntary. Recovery is gradual, and the possum will eventually move to safety on its own terms.
Why Possums Play Dead
The primary purpose of thanatosis is to deter predators that prefer to hunt live prey. Many predators, such as dogs, coyotes, and owls, attack moving targets and may lose interest in an animal that appears dead. The combination of the motionless body and foul odor, mimicking decay, makes the possum seem unappetizing or diseased.
This defense mechanism is a highly effective last resort when other strategies, like hissing, growling, or fleeing, have failed. By appearing dead and smelling unpleasant, the possum can often convince a predator it is not a worthwhile meal, avoiding attack and increasing its chances of survival.
What to Do When You Encounter a “Playing Dead” Possum
If you encounter a possum playing dead, leave it undisturbed. Provide the animal ample space and observe it from a distance. Do not touch, poke, or attempt to move the possum.
Interfering with the possum can prolong its state or, if it recovers prematurely, it might react defensively. The possum will eventually recover and move away once it feels the threat has subsided. Allowing it to recover naturally ensures its safety and prevents distress or defensive reactions.