I found a baby opossum. Does it need help?
The short answer
Measure the body from nose to rump, not counting the tail. Under seven inches, it needs a rehabilitator. Over seven inches, alert and running from you, it is old enough to be on its own. If it is close to that line, or you are not sure, call and describe what you are seeing.
Do not feed it. Do not give it water. Put it somewhere warm, dark and quiet, and call.
The size rule, and why it is a range
Opossums are the only marsupial in North America, and that changes the arithmetic. A joey is born after eleven to thirteen days of gestation at about the size of a bee, crawls into the pouch, and latches onto a nipple that then swells inside its mouth. It stays attached that way for roughly two months. Eyes open somewhere around eight to ten weeks. After that it rides on the mother's back until it is big enough to strike out alone.
The widely used cutoff is seven inches nose-to-rump, and that is the one to work from. Some rehabilitators prefer a more cautious margin of around eight inches, or a weight above roughly two hundred grams, before they will call a joey safely independent. If yours is somewhere in that range, we would rather you call than walk away.
Under seven inches, or eyes still closed: it is an orphan. Call.
Right around seven to eight inches: judgment call. Call and describe it.
Comfortably over seven inches, alert, and it runs off or hisses and drools at you: leave it alone.
That last behavior matters as much as the tape measure. A healthy juvenile opossum reacts to you. It runs, or it opens its mouth wide and hisses and drools, or it goes stiff and catatonic. A joey that needs help is cold, limp, quiet or crying, and does not try to get away.
If the mother was hit by a car, check the pouch
This is the single most useful thing anyone reading this can do, and almost nobody knows to do it.
A female opossum hit on the road often dies with a pouch full of living young. They can survive in there for hours after she is gone. If you can safely pull over — meaning there is a shoulder, you are not on a blind curve, and you are not stepping into a live lane — put on gloves and check the lower abdomen for a pouch.
Two cautions. First, traffic is the actual danger here, not the opossum. No animal is worth getting hit for. Second, she may not be dead. Playing possum is not a decision the animal makes; it is an involuntary catatonic state that can last for hours, and it comes with drooling and a slowed heartbeat. Gloves, always.
Also look on the ground around the body. Impact can throw joeys clear of the pouch.
Do not pull a latched joey off
This is the part people get wrong with the best intentions.
Because the nipple swells inside the joey's mouth and throat, this is not a suction grip that pops loose. Pulling tears the mouth, the palate, or the jaw. We have seen the result and it is not fixable in a young animal.
If the joeys are attached, put the whole mother into a ventilated box lined with a soft cloth — a towel with no loops or frayed threads, which snag toes and teeth — and bring the entire thing to a rehabilitator. We separate them with the right technique. If a joey is clearly furred, eyes open, and not attached to anything, you can lift it into a warm container on its own.
What to do in the first hour
Contain it. A cardboard box or carrier with a secure, ventilated lid, lined with a ravel-free cloth.
Warm it. A heating pad on low under half the box, or a covered hot water bottle inside it. Always leave an unheated half so the animal can move off the heat if it needs to.
Nothing by mouth. No food, no water, no milk, no Pedialyte.
Dark and quiet. No pets, no children, no passing it around to show the neighbors.
Call. Text us at 901-340-6534.
On the feeding point: you will find websites that give the public emergency formula instructions. We are not going to. A cold animal cannot digest anything, wild babies aspirate milk into their lungs very easily, and the wrong formula for even a week or two causes permanent bone damage. If a rehabilitator tells you to give something over the phone, do that. Otherwise the correct answer to what do I feed it is nothing.
Call right away if you see any of these
Bleeding, an open wound, or an obviously broken limb.
Any contact with a cat or a dog, even with no visible injury. Cat saliva carries bacteria that kill small mammals within a couple of days without antibiotics.
Fly eggs or maggots. Fly eggs look like small grains of rice clustered in the fur or around the eyes, nose and mouth.
Cold to the touch, wet, or crying continuously.
Eyes still closed.
Found on or near a dead mother.
The rabies question
Opossums very rarely carry rabies. The explanation you will read everywhere is that their body temperature runs low, around 94 to 97 degrees, which is thought to be inhospitable to the virus.
That is a plausible hypothesis, not a proven mechanism, and we would rather be accurate than reassuring. Rabies in opossums is rare, not impossible — a naturally infected opossum was documented in Brazil as recently as 2021. Opossums are not a rabies reservoir species in the United States and they are not on Tennessee's rabies vector list. But handle any wild mammal with gloves, and treat any bite the way you would treat any wild mammal bite.
About those ticks
You have seen the meme: an opossum eats five thousand ticks a week, so put out cat food and let them protect your yard from Lyme disease.
We would love for that to be true. It mostly is not, and it is worth correcting because the opossum deserves an honest defense.
The original 2009 study was real, but it does not say what the meme says. Captive opossums were deliberately infested with larval ticks, and they groomed off about 96 percent of them, far more than mice did. From that result the researchers back-calculated that an opossum would have to be carrying upwards of five thousand larval ticks in a given week at the peak of larval season for that many to have fed successfully.
That number was never a count of ticks eaten. It was an inference about tick burden, drawn from captive animals that had been deliberately infested. On the way to social media, groomed off quietly became hunted down and eaten, and a laboratory extrapolation became a yard management strategy.
Then in 2021 researchers examined the stomach contents of thirty-two wild opossums in Illinois and found no ticks at all — not one, not a fragment — even on animals carrying ticks on the outside. They also reviewed twenty-three earlier opossum diet studies covering well over a thousand stomachs. None of those found ticks either.
So: opossums groom themselves thoroughly, which kills ticks that try to feed on them. They do not appear to hunt ticks or eat them meaningfully, and putting food out to attract them will mostly attract raccoons, rats and free-roaming cats.
Opossums are worth having around on their own merits. They clean up carrion and rotting fruit, they eat a great many insects and snails, they are gentle, and they almost never bite anything that is not food. That is enough. The tick statistic was never the reason.
Who we are
Out of the Woods Wildlife Rescue & Rehab is a wildlife rehabilitation nonprofit in Memphis, permitted by the Tennessee Wildlife Resources Agency. Opossums are one of the species we are permitted for and one of the species we see most. If you have found one and are not sure, text 901-340-6534 with a photo and the measurement.
Two practical notes. Rehabilitators do not drive out to pick animals up, so you will need to transport. And in Tennessee it is illegal for an unlicensed person to keep or treat wildlife, which is less about punishment than about the fact that it almost never ends with a released animal.
Sources: Opossum Society of the United States. Wildlife Center of Virginia. Tufts Wildlife Clinic. Keesing et al. 2009, Proceedings of the Royal Society B. Hennessy and Hild 2021, Ticks and Tick-borne Diseases. University of Illinois Extension. TWRA rehabilitator permit rules.
We are wildlife rehabilitators, not lawyers or veterinarians. TWRA is the authority on Tennessee law.