For most of the night, an opossum is a silent animal. It moves through its territory with deliberate quietness, foraging along fence lines and through leaf litter without the crashing and banging associated with raccoons. When you do hear an opossum, the sound is almost always meaningful — a specific signal with a specific function. Understanding the opossum's acoustic repertoire tells you a great deal about its behavior, its social structure, and whether the animal near you needs to be left alone.
The Hiss: A Warning, Not a Threat
The hiss is the opossum sound most people have encountered, usually as a result of surprising one at close range. It is a sustained, forceful exhalation with a raspy quality — sometimes accompanied by an open-mouthed display that exposes all 50 teeth. The effect is startling and is designed to be. The opossum is telling you it knows you are there and it wants you to leave.
The critical distinction is that hissing is a defensive warning, not a prelude to aggression. The opossum hissing at you is frightened, not preparing to attack. Its entire behavioral strategy in this moment is aimed at making you back away, not at closing the distance between you. If you simply step back and give it space, the hissing will stop within seconds and the animal will resume its normal behavior or retreat into cover.
Step back slowly and give the animal a clear escape route. Do not approach it further, crouch toward it, or attempt to handle it. In almost every case, the hissing will stop within 30 seconds and the opossum will move away on its own. No intervention is needed or helpful.
Hissing is accompanied by other visual signals: the animal will typically stand its ground with all four feet planted, raise the fur along its back slightly, and hold its mouth open wide. This entire display is called deimatic behavior — a threat posture intended to deter without requiring physical conflict. If the display fails to drive away the threat, the opossum's next move is often to collapse into the immobile, unresponsive state known as thanatosis — playing dead — rather than to fight.
Clicking and Lip-Smacking: Contact Calls
The clicking sound produced by opossums is the opposite of a hiss in every respect. Where the hiss is loud, forced, and aggressive in intent, clicking is quiet, rhythmic, and affiliative — used to maintain contact between individuals who want to stay near each other.
Mother and Joey Communication
The most biologically important use of clicking is between a mother and her joeys. Once joeys have grown large enough to leave the pouch and ride on their mother's back — at roughly 70 to 80 days of age — they communicate with her through a near-continuous soft clicking or sneezing vocalization. This sound is made at low amplitude and is not easily audible to human ears more than a few feet away.
The clicking serves a critical survival function. Mother opossums move constantly while foraging, navigating through dense vegetation, over obstacles, and across variable terrain. Joeys, clinging to their mother's fur, sometimes fall off. The clicking allows the mother to locate a displaced joey in the dark, precisely and quickly, without exposing either of them to predators through louder vocalizations. When a joey falls silent, the mother investigates. The communication is efficient, quiet, and effective.
Courtship Clicking
Adult opossums also use clicking during courtship. Males and females approaching each other during breeding season produce a series of clicking and lip-smacking sounds that appear to function as identity signals — communicating species, sex, and potentially reproductive readiness. This is a relatively understudied aspect of opossum communication, but field observers have noted that the sounds reliably precede mating behavior and are distinct from the harsher sounds of aggressive interaction.
Screeching: Extreme Distress
The screech — a sharp, high-pitched vocalization — is the sound of an opossum in genuine distress. It is relatively rare. Most opossum encounters, even stressful ones, produce hissing rather than screeching. The screech signals a level of threat or pain that has exceeded what defensive posturing can address: physical contact with a predator, injury, or entrapment.
If you hear a screeching sound from an opossum, the animal is likely injured, caught in something, or actively being attacked by a predator. In those circumstances, the appropriate response for most people is to call a licensed wildlife rehabilitator rather than to attempt intervention directly. Injured wildlife of any species should be handled by trained professionals.
Low Grunts and Chuffing: Contentment and Foraging
Opossums foraging peacefully produce low, quiet grunts and a soft chuffing sound — a short, breathy exhalation. These sounds are heard most often when an opossum is actively eating or moving through particularly productive foraging habitat. They are not loud enough to be reliably detected by a person standing more than a few feet away, and most people who have shared their yard with an opossum for years have never consciously heard them.
These quiet vocalizations may serve to maintain awareness of the animal's own presence in an environment where other opossums occasionally forage nearby. Opossums are not strongly territorial but do give each other space, and low-level acoustic signaling may help individuals locate and avoid each other during overlap periods.
Growling: Rare and Escalated
A true growl from a Virginia opossum is uncommon. It represents an escalated threat response, typically seen in situations where a cornered opossum has hissed without success and is experiencing ongoing close-proximity pressure from a threat. The growl is lower-pitched than the hiss and more continuous. It very rarely precedes a bite from a healthy adult opossum — at this point the animal is more likely to shift to thanatosis than to initiate contact — but it is a clear signal that the animal's stress level is high and that increased distance from it is the appropriate response.
Non-Vocal Communication: Scent and Body Language
Vocalizations are only one channel through which opossums communicate. Scent marking plays a significant role in their social lives, even though opossums are not as conspicuously scent-oriented as mustelids or canids. They possess sternal and anal scent glands used to mark trails, resting sites, and possibly reproductive status. The smearing of secretions from the sternal gland during social interactions has been documented in closely related species.
Body language also carries substantial information. The full open-mouth display is the most dramatic signal, but subtler postures matter too: an opossum facing directly away from a threat and moving slowly away is signaling retreat, not attack. One that stops moving and stands very still is often in the early stages of the thanatosis response, even before it has fully collapsed. These behavioral cues are worth learning to read because they tell you exactly what the animal is experiencing and what it is likely to do next.
Hiss: defensive warning when threatened. Click: contact call between mother and young, also courtship. Screech: extreme distress or injury. Low grunt/chuff: contentment during foraging. Growl: rare, highly escalated threat response. Opossums are among the quieter suburban wildlife species — most of their activity is conducted in silence.
When Are You Most Likely to Hear Them?
Opossum vocalizations are most commonly heard during the breeding season, which peaks in January through March for the first litter and again in May through July for the second. During breeding, males and females encounter each other more frequently than at other times of year, increasing the likelihood of both courtship clicking and antagonistic hissing between competing males.
Early summer is also when young opossums disperse from their mothers, often encountering other animals — including humans and domestic pets — for the first time. Young opossums are more likely than adults to screech and hiss vigorously when startled because they have not yet learned when a threat is serious and when it is not. If you find what appears to be a very small opossum hissing defensively at you, its behavior is fear-based and entirely harmless. Give it an escape route and it will take it.
Understanding the sounds of an opossum is ultimately an exercise in reading an animal's emotional state clearly and accurately. A hissing opossum is not dangerous — it is scared. A clicking opossum is content or seeking contact with young. A screeching opossum needs help it cannot give itself. The vocabulary is small, the meanings are clear, and responding appropriately requires only the willingness to listen before reacting.