Virginia Opossum

One to two litters a year, and the pouch is what makes the timing unforgiving. Gestation is only 12 to 13 days, but pouch development runs another 7 to 8 weeks on top of that, and the young are not fully weaned until roughly 3 months old. Warmer climates commonly see 2 litters and rarely 3, while 1 litter a year is typical in northern populations. That means for a large part of the year an opossum denning under a deck is a female with young you cannot see and cannot count. Confirm the den is empty before anything gets closed up.

Size and build put it in house-cat territory

Adults run 24 to 33 inches of total length including the tail, with a documented maximum around 40 inches, and weigh 4 to 15 pounds. Males average 6 to 7 pounds and reach about 14, while females average closer to 4. The tail is slightly less than half the total length.

Color is the least distinctive part

Color is the least distinctive thing about it. The fur is white or grayish, tipped with gray or black guard hairs. What reads at a glance instead is the head: a long, narrow, pointed snout ending in a pink nose, and bare, rounded ears that are black on the inside.

Three features separate it

Nothing else on the continent has all three. It has 50 teeth, more than any other North American land mammal. Its tail is prehensile, nearly hairless, and rat-like, running almost as long as the body. And each hind foot carries an opposable, clawless inner toe that works like a thumb, which is what makes an opossum a genuinely good climber.

Raccoon, settled by tracks

The animal to rule out is the raccoon, and tracks settle it. Both leave five-toed prints and both get blamed for the same overturned garbage can at 2 in the morning. The difference is the hind track: an opossum's shows that opposable thumb toe with no claw, which gives the print an odd baby-handprint look, while a raccoon's hind track reads as an ordinary foot. From a distance the face and tail do the same job. An opossum has no mask and no ringed tail, just a plain pointed snout and a bare tail.

A stubby tail is frostbite

A northern opossum with a stubby tail or ragged ears is not a different animal. Both the ears and the tail carry almost no fur and are highly prone to frostbite in cold-climate populations. A tail that looks too short for the body is usually tissue lost to frostbite rather than natural variation, and it is one of the more reliable tells that you are looking at an animal living at the cold edge of the range.

Tracks, and specifically the hind track

Five toes register on both front and hind feet, but the hind foot's opposable clawless thumb toe is the giveaway, producing that small handprint impression nothing else in the yard leaves. Front and rear tracks usually fall close together, with the rear landing on or just behind the front. A tail-drag mark may show if the animal was moving slowly, though opossums normally carry the tail up while walking.

A borrowed den rather than a built one

Because opossums do not dig or construct dens, the sign is disturbance rather than excavation: insulation pushed around in an attic, nesting material dragged into a garage or shed, dry leaves or shredded paper heaped under a deck or porch. It tends to look messy and improvised, because it is.

Sound is a weak sign here

That is itself useful to know. Unlike a raccoon's chattering or a skunk's warning stomp, there is no distinctive passive noise that tells you an opossum has moved in. The documented vocalizations, hissing, growling, and screeching, are defensive and happen when the animal is directly confronted, not while it is quietly denning. Do not wait to hear something.

A warning sequence, then the famous one

If you get close, you will get a warning sequence, and then possibly the famous one. A threatened opossum typically bares its teeth, growls, and hisses first, and may exude a smelly greenish fluid from its anal glands. Only if the bluff fails does it play possum, and that is worth understanding correctly: the collapse is an involuntary, fainting-like catatonic state, not a performance the animal decides to put on. It is more common in young opossums than in adults, which more often just stand their ground or leave. A motionless opossum in the yard is usually neither dead nor sick. The right response is to give it distance and time rather than to handle it or dispose of it.

Odor is real but mild

A denning opossum can leave a musky, sometimes garbage-like smell, and a cornered one can release defensive musk from its anal glands. Both are far milder and far less persistent than skunk spray, and the smell alone will not tell you which animal you have.

Raided food is the first complaint

Raided food sources are the most common first complaint. Opossums are opportunistic omnivores and scavengers whose main dietary component is carrion, supplemented with insects, earthworms, fruits, berries, bird eggs, amphibians, and plants. Near people that translates directly into garbage cans, compost piles, bird feeders, and pet food dishes left out overnight, which is what brings most of them onto a property in the first place.

Start with the food

Start with food, because food is what brought the animal to the property. Do not leave pet food outdoors overnight. Clean up spilled birdseed under feeders. Secure garbage in cans with tightly fastened lids, and if the lid still comes off, a rubber strap across it is the specific low-cost fix the USDA and university extension wildlife damage handbook names. Compost piles and fallen fruit belong on the same list. An opossum is a scavenger before it is anything else, and a property with nothing worth scavenging is a property it passes through rather than settles on.

Close the denning sites

An opossum can only take over a space that already exists. Shut off the area under decks and porches with hardware cloth in half-inch or one-inch mesh, running it from the top of the joists down into a trench at least 10 inches deep and angling the buried edge outward at the base. Check and repair loose fascia boards, chimney caps, and attic vents on a regular schedule, because those are the openings an opossum will use if it finds them. Store firewood away from the structure and at least a foot off the ground so it stops functioning as cover. Confirm nothing is inside before sealing anything, especially in spring and summer, when a female may have young in the pouch or riding on her back.

If you use wire mesh, add a wire

If a wire-mesh fence is the barrier, add one wire. Opossums are capable climbers, so mesh alone does not stop them. A tightly stretched electric fence wire near the top of the fence, offset a few inches out from the mesh, deters climbing over. This is a specific, tested detail from the USDA and university extension wildlife damage handbook rather than a general fencing suggestion.

Horse owners have a reason

No other property owner does. The Virginia opossum is the only confirmed definitive host in North America for Sarcocystis neurona, the parasite responsible for the great majority of cases of Equine Protozoal Myeloencephalitis, a degenerative and potentially fatal neurological disease in horses. Horses pick it up by eating feed or drinking water contaminated with sporocysts shed in opossum droppings. The horse is a dead-end host and cannot pass it on. Veterinary guidance is blunt about how tightly the two are linked: the range of the opossum defines the geographic range of clinical EPM in horses. The practical step is straightforward, which is to keep feed and water sources sealed and inaccessible to opossums on any horse property.

Do not feed them on purpose

Do not feed opossums on purpose, and the usual reason people do is not true. The popular claim that an opossum eats thousands of ticks a season traces to a 2009 laboratory study that put 100 larval ticks on 4 captive opossums, recovered only about 3.5 ticks on average from the cage floors afterward, and extrapolated from that gap to a figure above 5,000 per season. A national conservation magazine amplified a related version of the number in 2015. Nobody in the original study checked the animals' stomach contents or combed them before release. When researchers did exactly that in 2021, dissecting the stomachs of 33 wild-caught Virginia opossums, they found worms, fleas, and a French fry, and zero ticks in any of them. The same team reviewed 23 earlier diet studies covering more than 1,280 opossums going back to 1851 and found not one report of ticks in the diet. Their proposed explanation for the missing lab ticks is that opossums have a lower metabolism, body temperature, and blood pressure than the other species tested, ticks feed more slowly under those conditions, and the ticks that seemed to vanish were most likely still attached and feeding when the animals were released. Opossums do eat insects and other invertebrates as part of a broad omnivorous diet, and that much is real, just modest and unquantified. Feeding them anyway also draws in raccoons, feral cats, rats, foxes, and coyotes, and raises disease-contagion risk across all of them.

On rabies, this one breaks the pattern

On rabies, this species genuinely breaks the pattern, and the nuance matters. An opossum's body temperature runs about 94 to 97 degrees Fahrenheit, low enough that the rabies virus has a harder time surviving and replicating, and low enough that an opossum is unlikely to survive an attack by a rabid animal in the first place. That mechanism is not folklore. It is stated by the National Park Service, by a peer-reviewed veterinary case report, by a University of Illinois Extension wildlife source, and by a university mammal database, all independently. The Virginia opossum is not among the species identified as rabies reservoirs the way raccoon, skunk, fox, and bat are. None of that adds up to immunity. Resistant is not immune, opossums can still carry and transmit the virus, and any bite or scratch from one still needs to be treated as a possible exposure and evaluated by a physician, exactly as you would treat a bite from any wild mammal. Opossums are also documented carriers of a long list of internal and external parasites, including fleas and ticks, which is a separate matter from the diet question above.

Rules vary, two examples

Trapping and relocation rules vary by state, and two documented examples show how much. Illinois treats the opossum as a protected furbearer with an open trapping season and requires a nuisance animal removal permit from a district wildlife biologist for a homeowner who wants to trap and remove one in an urban area, or a hunting or trapping license in rural areas. New York's own nuisance-wildlife take rules require a state environmental agency permit to take an opossum specifically for being a nuisance. Those are two states' answers, not a national rule, and several states restrict moving a captured animal off the property where it was caught even more tightly than they restrict removing it. The USDA and university extension wildlife damage handbook says the same thing in general terms, that laws protecting opossums vary from state to state, and advises contacting local wildlife authorities before removing a nuisance animal. Check your own state's current rules before you trap anything.

Who to Call, and When

Call for any opossum denning under a deck, porch, or shed, or inside an attic, garage, or crawl space, because sealing an entry point without confirming the animal and any young have left traps them in a space you cannot reach. Call a physician for any bite or scratch, regardless of how minor it looks or how low-risk this species is in general. Call your veterinarian for any horse showing unexplained neurological symptoms on a property where opossums are present, so an EPM workup can run alongside the feed and water exclusion steps above. And call a licensed nuisance wildlife control operator for anything involving a trap. Opossums are easy to live-trap and are not trap-wary, which is exactly what makes it tempting to do it yourself and exactly why the legal side is worth handing to someone who works under a permit.