Possum vs. opossum?

We often use the term “possum” to describe opossum and possum species, but possums are not the same animal as opossums. Possums are a subfamily of marsupials native to Australasia. Opossums are a family of marsupials found natively in North, Central, and South America.

Your writing, at its best

Compose bold, clear, mistake-free writing with Grammarly's AI-powered writing assistant

What is the difference between possum vs. opossum?

Possums? Opossums? If you live in North America, you probably didn’t know there’s a difference between the two animals, and you’ve probably misused these terms. When people talk about “possums” in the United States, they’re most likely talking about the Virginia opossum, which is one of six opossum species belonging to the Didelphidae family. 

We typically use the word possum as an abbreviation for all opossums, but real possums belong to the Phalangeridae family. Opossums and possums are different animals that look and behave similarly at times. But in case you’re wondering–– the name opossum came before possum and was explicitly used for North American opossums. 

Why do people call opossumspossums”?

Depending on who you ask, the term aposoum or opassom is a Virginia Algonquian term for “white animal,” “white face,” or “white dog.” The indigenous term was adapted by colonist Captain John Smith of Jamestown, Virginia, to name the Virginia opossum (Didelphis virginiana) in 1610. The term opossum was shortened around 1613 and casually used to describe all opossums in the United States. 

The reason we use the term “possums” for specific Australian marsupials is thanks to Sir Joseph Banks. The 18th-century botanist encountered the animals during his explorations with Captain James Cook, and Banks thought the opossum-like animals were of the same tribe. 

A lot has changed since the 1600s’ and scientists now know that American opossums and Australian possums consist of different species. But do you? The Word Counter is going to break down every difference between possums and opossums, so there’s no room for confusion. 

Are possum and opossum the same thing?

Possums and opossums are marsupials, but they are not the same animal. Marsupials are a mammalian class of animals with over 250 other animal species. Marsupials share common anatomical traits such as having fur, mammary glands, a front pouch as an extension of their reproductive systems, and a noticeable stunt in brain development. Other marsupials include wallabies, kangaroos, bandicoots, and koalas.

What is an opossum?

Opossums are nocturnal marsupials found throughout the Americas. Most opossums belong to the Didelphidae family of the Didelphimorphia order, but there’s also the shrew opossum that belongs to the Caenolestidae family of the Paucituberculata order. The Virginia opossum is the only marsupial found in the US, and all other opossums are native to regions in Central and South America. 

North American opossums (aka the Virginia opossum), are most recognizable from their white face and pink-colored nose.

What is a possum?

Possums are also nocturnal marsupials, but they belong to a different suborder of animals called Phalangeriformes, which are of the Diprotodontia order. The Phalangeriformes suborder contains two superfamilies, the Phalangeroidea and the  Petauroidea, and these two orders consist of six distinct possum species. All possums are native to Australia, New Guinea, Sulawesi, and are found invasively in New Zealand. 

Common ringtail and brushtail possums are known to sneak into homes to forage for food, but it’s hard to take this brushtail burglar seriously (Stilgherrian/Flickr).

What do you call a group of possum and opossum?

The words opossum and possum are singular, and the plural form is opossums or possums, respectively. Whether you’re in the Americas or Australasia, the biological term for a group of opossums or possums is called a “passel.” Finding a passel of adults in the wild is uncommon since opossums and possums are solitary creatures. An individual female is called a “jill,” a sole male is called a “jack,” and their babies are called “joeys.”

How to tell the difference between a possum and an opossum?

There are understandable reasons why opossums are confused for possums. For example, they are both found with white, black, brown, or tan fur, and sometimes feature trademark spots or stripes. Both animal families also prehensile tails to assist climbing, and certain possum species are found using them to hang from trees.

Most possums and opossums also have 3-5 fingers with an opposable hallux. Their clawless opposable thumbs allow them to grab objects, climb up trees, and sneak into closed spaces like a raccoon. Outside these distinct features, possums and opossums are very different from one another. This is especially true regarding skeleton structure, habitat, interactions with their environment, reproduction, and lifespans. 

Opossums have more teeth than possums

Opossums are recognizable by their long snouts and triangular-shaped jaw, but they are also known for having many teeth. Opossums have around 50 teeth and pronounced canines, tricuspid molars, and small incisors. Opossums are cute when they are babies, but when an adult opossum opens its mouth to hiss, its teeth are a troubling sight.

This opossum skeleton looks prehistoric, but opossums have existed for the last 70 million years and once roamed the Earth with dinosaurs. (Allen Gathman/Flickr).

Possums have a very different mouth structure that is shared by all animals classified under the Diprotodontia order. In fact, the term diprotodont means “two front teeth.” Diprotodontia animals like possums also have pronounced incisors; they lack canines and have a much shorter jaw. Possums just don’t have an intimidating mouth like their opossum counterparts, and their snouts tend to resemble those of a mouse.

Just look at it. Brushtail possum eating fruit. (Peter Firminger/Flickr). 

Opossums are slightly larger than possums

Opossums are generally larger than possums, but not by very much. Between the Water opossum, Bare-tailed woolly opossum, Gray four-eyed opossum, and the Virginia opossum, the average adult body length ranges between 6.3-37 inches in length (excluding the tails). The smallest opossum noted is the Bare-tailed wooly opossum, which only grows to 6.3-10.2 inches. The largest opossum is the Virginia opossum, which grows between 1-3 feet in length! 

Possums have a smaller body frame that ranges between 2.6 inches to 1.9 feet in length. The Common and Mountain brushtail possums are two of the largest possums in Australia, where adults can grow nearly two feet in length. The Tasmanian pygmy possum is tiny in comparison to other possum and opossum species, reaching 2.6-3 inches in length.

Opossums produce more babies per year than possums

In ideal circumstances, opossums give birth nearly twice as much per year than possums and deliver almost twice as many babies at once. Between the four opossum species mentioned above, the number of births per year ranged between one and four. In contrast, possums generally give birth 1-2 times per year, although Western and Eastern pygmy possums can mate up to three times if conditions are right. 

Possum and opossum birth rates are susceptible to climate and habitat interferences, which means it’s hard to determine if one animal is more reproductively successful over a year. For example, the Virginia opossum can mate 1-3 times a year, but if the weather is too cold or food becomes scarce, offspring can quickly perish, or the animal may be forced to leave its regular breeding grounds. 

Mother opossums carry “joeys” on their backs until they leave the nest (Monica R./Flickr). 

Opossums do produce more babies at once, though, and therefore with more frequency. The opossum’s reproductive anatomy is also different from the possum, which may allow them to produce more young at one time. Female opossums have a bifurcated vagina and divided uterus, and males have a bifurcated penis, which means the animal’s bifurcated anatomy splits into two parts. 

The average opossum litter ranges between 3-7 babies while possum litters remain small with only 1-3 babies per birth. For both possums and opossums, the number of viable newborns is limited to how many teats each female species has. The Virginia opossum has 13 nipples, so even if it gives birth to 20 “joeys,” only 13 have a chance at survival. Depending on the species, female opossums have 5-13 nipples available to offspring, while female possum species are limited up to six. 

Baby possums take longer to mature than opossums

While opossums outnumber possums reproductively, possums can live longer and breed more throughout their lives. As marsupials, most possums and opossums have a pouch on their belly to store babies. These pouches are not as cute and mobile as kangaroo pouches, but they work just as well for nursing and protection. 

On average, baby possums spend more time in their mother’s pouch than baby opossums, and they take substantially longer to leave their mother’s nest. Species of pygmy possums can take anywhere from 26-65 days to exit the pouch while the larger possums hang out for 4-6 months. 

Possum babies stick around the nest for about as long as they were in the pouch. However, species that produce more babies per litter leave the nest earlier than “only-child” possums. The most extended time occurs with the Mountain brushtail possum, which lives with its mother for the first 18-36 months. 

Opossum babies live in their mother’s pouch around 40-90 days and are ready to live on their own after four months. After leaving their mother’s pouch at 60 days, baby Virginia opossum climbs onto their mother’s back and ride along until they are ready to leave the nest. Other large possum and opossum mothers carry their babies on their backs until they are ready to leave as well. 

Possums live longer than opossums

On average, possums survive longer than in opossums in the wild and captivity. In the wild, possums are reported to live anywhere between 1-15 years and about 3-16 years in captivity. Pygmy possums have shortest wild life spans of possums (1-3 years), but this is normal for wild opossums. Opossums in captivity rarely reach the age of nine, and wild opossums seldom live beyond three years. 

There are several reasons why possums can outlive opossums, whether it’s nearby predators, pest control, environmental disasters, climate change, or nearby human habitation. Because species like the Virginia opossum eat dead animals on the sides of roads at night, they are more likely to die from car drivers who cannot see them. The range of opossum predators in North and South America is diverse too, whether it’s large birds, domestic pets, coyotes, bobcats, snakes, or foxes. 

Opossums can “play possum

What’s fascinating about the opossum’s short lifespan and predator range is how many opossum species are capable of apparent death, or “playing possum.” Apparent death is an adaptive defense mechanism where an animal appears to be dead by stiffening its body, becoming unresponsive, and dropping body temperature. 

Other animal species are capable of apparent death as well, but opossums take this trait to new levels. In addition to curling up its lips,  and lying with its eyes and mouth opened, the opossum drools with its tongue out and secretes a foul-smelling odor to mimic the effect of the decomposition. “Playing possum” is physically involuntary for opossums and can last up to four hours. 

It’s not clear if all opossums are capable of apparent death, but certain opossum and possum species do become torpid during cold weather or times of food scarcity. Torpor isn’t the same as apparent death, but it is a survival mechanism that lowers body temperature and metabolism for extended periods until favorable conditions arise. 

Opossums and possums live in different habitats 

Since opossum and possum species live on separate continents, their natural habitats are different too. Found throughout most of the United States, the Virginia opossum prefers to live in damp ecosystems, whether it’s in forests, farmland, and marshy meadows. They live where they can eat and create dens, and so it’s common to find them cohabitating in urban environments as well. All other species of opossum have similar habitat preferences, which include areas near trees, shrubbery, water, and an abundance of territory to roam around. 

As for possums, you’re likely to find them wherever there are trees. Most possums are arboreal, which means they are tree-dwelling animals. Larger species like the common brushtail possum are sometimes found in urban areas, but this is because they can thrive in several different climates and ecosystems. Each possum species enjoys a diverse habitat throughout Australia’s vast territories, such as forests, open heathland, mountains, or coastal woodlands.  

Possums and opossum interact with their environments differently

Opossums are omnivores, so they eat fruit, vegetables, herbs, insects, domestic cat food, and small animals. But they also eat a lot of dead animals and food waste, which is why people report opossum activity near roads and garbage cans. While can-rummaging can be a nuisance to people, their scavenging habits are good for the environment and help animal control employees to keep carcasses off the streets. 

Opossums are also resilient to poisonous chemicals such as cyanide, they eat most ticks found on their bodies, and they’re immune to snake venom. This means opossums can eliminate a broad range of undesirable waste products, dangerous pests, and possibly help scientists to create the perfect antivenom. Opossums also act as a neutral barrier between rabies and other animals since their body temperature is typically too low to host and transmit the live virus. 

While it’s rare for opossums to have rabies, this isn’t to say they don’t spread other parasites and behave as friendly neighbors. As mentioned before, opossums hiss and show their sharp teeth when necessary. Opossums also camp under houses, porches, or sneak into attics, which is distressing and messy for homeowners and their pets. Opossums are fiercely independent, territorial, and can find smart ways around closed-off areas. 

Northern brushtail possums enjoy eating fruits and vegetables (Scarlet23/English Wikipedia). 

There are a few possum species in Australia with similar reputations to opossums, except most Australian species are protected. Species like the brushtail possum or Common ringtail possum are known as urban pests and known to invade homes for food when convenient. Possums don’t have the same virulent resilience as opossums, but they are resilient to many plant toxins. Australia has largely eradicated the threat of rabies, so the largest health risk possums pose to the public are diseases carried in droppings.

Possums mostly stick to eating plants, insects, eggs, and sometimes their own feces. More specifically, urbanized possums prefer to eat vegetables out of people’s gardens. 

Possums were introduced to countries like New Zealand to introduce fur trade and are now considered a major ecological issue. Invasive possum species prefer snacking on tree sprouts and bird eggs, which destroys foreign ecosystems they’re introduced. 

FAQ: Related to possum vs. opossum

Is the O silent in the word opossum?

The “O” in “opossum” is not silent and is pronounced to give the word three syllables.
The word opossum is pronounced “uh-pos-sum” or “oh-pos-sum.” 

Why is opossum pronounced possum?

The word “opossum” is not pronounced the same as “possum.” Informal, colloquial dialects in the U.S. shortened “opossum” to “possum.” 

Test Yourself!

  1. Choose the correct spelling for a “possum” found in South or North America.
    1. Opossums
    2. Opposums
    3. Oppossum
    4. Opossum 
  2. An individual female Water possum is called a ___________.
    1. Water Passel
    2. Jill
    3. Water Possum 
    4. Water Jill
  3. True or false: Opossum is not pronounced the same as possum. 
    1. True
    2. False
  4. True or false: Possums and opossums are immune to rabies. 
    1. True
    2. False
  5. Which of the following species are known as urban pests?
    1. Common brushtail possum
    2. Virginia possum 
    3. Common ringtail possum 
    4. All of the above

Answers

  1. D
  2. B
  3. A
  4. B
  5. D

Sources

  1. Alongi, J. “Opossum facts.” Animal Facts Encyclopedia, 2019. 
  2. Berkhouse, H. “Wyulda squamicaudata: scaly-tailed possum.” Animal Diversity Web, 2015. 
  3. Burramys Parvus (mountain pygmy-possum) conservation advice.” Threatened Species Scientific Committee, Australian Government Department of Environment and Energy, 2 Jan 2018. 
  4. Gardner, A. “Water opossum.” Encyclopedia Britannica, n.d. 
  5. Gardner, A. “Four-eyed opossum.” Encyclopedia Britannica, n.d. 
  6. Jeffrey, A. “Caluromys philander (bare-tailed woolly opossum).” The Online Guide to the Animals of Trinidad and Tobago, The University of the West Indies at St. Augustine, Trinidad and Tobago, 2012. 
  7. Little pygmy-possum.” Atlas of Living Australia, n.d. 
  8. Marsupial.” Encyclopedia Britannica, n.d. 
  9. Opossum.” The Merriam-Webster.com Dictionary, Merriam-Webster Inc., 2020. 
  10. Opossum Problems and Solutions.” Opossum Society of the United States, 2020.
  11. Orphaned or injured opossum.” Opossum Society of the United States, 2020.
  12. Possum.” The Merriam-Webster.com Dictionary, Merriam-Webster Inc., 2020. 
  13. Possums and other animal pests.” Northland Regional Council, n.d.
  14. Possums as pests: Signs, symptoms, prevention and control.Pestrol Australia, 2019. 
  15. Pygmy possums.” Bush Heritage Australia, 2020.
  16. Sharman, GB, “Observations upon the animals made by the naturalists of the ‘Endeavour,'” Oceania 44(3): 216–232, 1974.
  17. Stanvic, S. “Possums: juvenile to adult.” Tasmanian Wildlife Rehabilitation Council, 2006. 
  18. Virginia opossum.” The Virtual Nature Trail at Penn State New Kensington, The Pennsylvania State University, 12 July 2006.