An opossum playing dead is not acting. When a possum keels over, stiffens up, and lets its tongue loll out, it has not decided to do this. Its nervous system has done it without asking permission. The state can last from a few minutes to about four hours, the animal stays aware the whole time, and the right thing to do if you find one is to walk away and give it room.
Do possums really pretend to be dead?
No, not in the way the word suggests. Pretending requires a decision, and there is no decision here. What gets described as a possum pretending to be dead is an involuntary reflex called thanatosis: the animal collapses because its nervous system has taken the choice away from it, which puts it closer to fainting than to acting.
The giveaway is that the state cannot be switched off on demand. A possum in it can be prodded, picked up, and carried while the mouth stays open and the body stays limp, which is not something an animal faking it would sit through. It also arrives with a smell, released from glands near the tail, and volunteering a smell like that is not a detail a performer would add for realism. So the honest answer is that possums do not pretend. They shut down, involuntarily, and the result is more convincing than pretending would be.
Why do opossums play dead?
The technical name is thanatosis, and it is closer to a seizure than a strategy. Being looked at does not set it off. In a 1985 field study, four free-ranging opossums that were approached by a person or a dog only froze, with their heart rate down about 12 percent. What tipped them over was being grabbed: vigorous handling by the investigator or the dog. Then the body went stiff, the mouth fell open, heart rate dropped 46 percent, from about 222 to 120 beats a minute, breathing slowed by 30 percent, body temperature dipped, and the animals stopped responding to touch or pinching. Every episode came with drooling, urination, and defecation, and a foul-smelling fluid from glands near the tail does most of the actual work of convincing a predator that this is not a meal worth finishing.
Recovery is just as involuntary. The animal comes back gradually, often beginning with a twitch of the ears, and only moves off once its nervous system has settled on the idea that the threat has passed. Nothing about the timing is a decision.
How long does an opossum play dead?
Anywhere from a few minutes to about four hours, according to the Opossum Society of the United States, which takes the calls from people who find one. There is no fixed clock: the episode ends when the animal's own system decides the danger has passed, and the first sign is usually the ears, which start to wiggle before anything else moves.
Is it dead or just playing dead, and what should you do?
From a few feet away the two look the same, which is the point. Mouth open, tongue out, body limp or stiff, no reaction to a nudge, and a smell that says it has been dead for days. The tells are small: the chest still rises, slowly, and the ears will start to twitch when the animal is about to come around.
Treat every dead-looking opossum as a live one for the first few hours. Leave the area, bring dogs inside, and do not put it in a bag or a trash can. If it is clearly injured, call a wildlife rehabilitator rather than handling it yourself. If the animal really is dead and it is a female, check the pouch. The young cannot survive long outside it, and a rehabilitator can raise them if they arrive quickly.
Is the opossum conscious while it plays dead?
Apparently yes, and this is the part that makes the whole business worse rather than better.
In 1964 a team recorded the brain activity of opossums in the feigning state and published the result in Nature. The electroencephalograph showed no significant difference between an opossum playing dead and an opossum awake and alert. Whatever is happening, it is not a blackout. The 1985 field study reached the same conclusion by a different route: when the dog came back toward a feigning possum, its heart rate dropped again. A blacked-out animal does not notice a dog.
So the popular description has the mechanism backwards in both directions. It is not a clever performance, because the animal did not choose it. And it is not a merciful unconsciousness, because the lights appear to stay on. It is closer to being locked in the room while something decides whether to eat you.
What other animals play dead?
Plenty, and none of them go as far. A 2024 review by Susana Monsó and Laura Danón lines them up: turkey vultures flatten on their bellies and stay put even when lifted off the ground, some frogs flop onto their backs with their tongues out, and hognose snakes writhe through a theatrical death first and then lie still with blood at the mouth. The opossum is the one that adds a cooler body, a bluish tongue, and the smell of decay to the act, which is why the review calls it one of the most elaborate displays in the animal kingdom.
Where "playing possum" came from
"Possum" itself is a 1610s American clipping of "opossum", and the phrase "play possum" is attested by 1822, meaning to feign death when threatened. It has since widened to cover any convincing performance of harmlessness, weakness, or disinterest, usually by someone who is none of those things. The irony, given what is actually happening physiologically, is that the animal the phrase is named after is not performing anything at all.
The most Do Not Perceive Me move in nature
We have written before about the philosophy behind not wishing to be perceived, and the opossum has always been its patron animal. Most creatures on that list are choosing to hide. The opossum has taken it a step further: it stops being available for the encounter without ever leaving it.
From the archive
The full opossum lineup, unbothered, mid faint, and otherwise, lives in Opossum Shirts. It also keeps close company with the toads, mushrooms, and other unglamorous specimens in Goblincore Shirts, and the original case file is still open in Do Not Perceive Me. Printed on heavyweight Comfort Colors cotton, for anyone who has, at some point, also wanted to just stop being present for an encounter.
Sources
- Francq, E.N. “Behavioral aspects of feigned death in the opossum Didelphis marsupialis.” American Midland Naturalist 81, no. 2 (1969): 556-567. The behavioral description of the posture, the flexed body and digits, and the finding that tactile contact rather than a sham attack is what triggers it.
- Norton, A.C., Beran, A.V., and Misrahy, G.A. “Electroencephalograph during ‘feigned’ sleep in the opossum.” Nature 204 (1964): 162-163. The EEG evidence that the feigning animal is not unconscious.
- Gabrielsen, G.W., and Smith, E.N. “Physiological responses associated with feigned death in the American opossum.” Acta Physiologica Scandinavica 123, no. 4 (1985): 393-398. Heart rate, respiration and body temperature during the episode, the freezing response to approach alone, and the heart rate dip when the dog returned.
- Monsó, S., and Danón, L. “Death-feigning, animal concepts, and the use of empirical case studies in animal cognition.” The British Journal for the Philosophy of Science (2024). The comparison of thanatosis displays across species and the description of the opossum's as one of the most elaborate.
- Opossum Society of the United States. “Opossum FAQ.” Duration of a few minutes to four hours, the ear wiggle before revival, what to do when one is found, and checking a dead female's pouch.
- Online Etymology Dictionary. “possum.” The 1610s clipping and the 1822 attestation of “play possum.”