With their pointy noses and bald tails, opossums can look like a strange kind of cat at first glance. But looks can be deceiving! Opossums and cats actually have some big differences when it comes to their biology, behavior, habitat, and more.
If you’re short on time, here’s the key difference between opossums and cats: Opossums are marsupials that carry their underdeveloped babies in a pouch, whereas cats are placental mammals that carry well-developed fetuses internally and give birth to living young.
In this comprehensive guide, we’ll explore all the ways opossums and cats differ, including their physical features, reproduction, diet, habitat, lifespan, and behaviors. You’ll learn fascinating facts about these mysterious marsupials and our furry feline friends—and why mistaking one for the other would be a major mistake!
Anatomy and Physical Features
Body Shape and Size
Opossums have a distinctly different body shape and size compared to cats. Opossums have an elongated snout, rounded ears, and a long, cylindrical body. They are about the size of a house cat, typically measuring 13-37 inches long from their nose to the tip of their tail.
Opossums are also generally heavier than cats, weighing 4-15 pounds on average.
In contrast, cats have a more petite, agile build with a rounded head, triangular ears, and a long, slender tail. House cats are typically 8-10 inches long without their tail, and weigh between 4-10 pounds on average.
Fur and Coloration
The fur of opossums is thick and coarse. They have a white face with dark fur covering the rest of their body. The fur on an opossum’s belly is usually lighter gray or white. Opossums do not have much variation in coat colors or patterns.
Cats, on the other hand, come in a huge variety of colors and patterns. Some common cat coat colors are black, white, orange, grey, calico and tabby. Cats generally have fine, smooth fur that is soft to the touch. Their fur and coloring provides camouflage and helps them hunt prey more effectively.
Teeth
One of the most distinguishing features between these two animals are their teeth. Opossums have 50 very sharp teeth specialized for an omnivorous diet of fruits, insects, snails, mice and carrion. They have more teeth than any other North American land mammal!
In comparison, cats have only 30 teeth adapted for an obligate carnivorous diet. Their long canine teeth are effective for seizing prey, while their molars help shear meat into swallowable chunks.
Claws
Opossums have opposable, clawless thumbs on their back feet. This helps them climb and grasp branches. The remaining toes have claws to aid in climbing. Their clawless fingers also enable them to more easily forage for food.
Cats have sharp, retractable claws on all four paws that are used for hunting prey and climbing. When not in use, their claws are neatly sheathed to maintain sharpness. The claws are curved and help cats gain traction and grasp surfaces when pouncing on prey.
Tails
Opossums and cats both have notable tails, but with some key differences. Opossums have a long, hairless tail that can wrap around branches. Their tail is prehensile and used like an extra limb. An opossum’s tail is typically as long as its body from 12-35 inches.
A cat’s tail tends to be about 1/3 its body length. Cats use their tail for balance and communication. A tail held upright signals a happy, friendly cat, while a swishing tail often indicates irritation. Cats also rely on their tail for stabilization when jumping and pouncing.
Reproduction
Gestation Periods
Opossums have remarkably short gestation periods compared to cats. The Virginia opossum gestation period lasts just 12-13 days, while domestic cats have a gestation around 65 days. This huge difference likely arises from the opossum’s marsupial reproductive strategy – their young are born extremely early, undeveloped, and must finish growing in the mother’s pouch.
Number of Offspring
Opossums give birth to very large litters, especially for such small mammals. A mother opossum may have 5-25 joeys in a single litter. Cats tend to have much smaller litters, averaging around 4-6 kittens.
So while cats invest more resources and time into each individual offspring, opossums take more of a “quantity over quality” approach, producing many offspring but providing each with less postnatal care.
Level of Development at Birth
Opossum joeys are extremely undeveloped at birth – they are essentially embryos. Blind, deaf, hairless, and only the size of a honeybee, they must crawl from the mother’s birth canal to her pouch completely unaided. There they each attach to a teat for the next 2-3 months.
By contrast, kittens are fairly well-developed at birth. They can see and hear, have a full coat of fur, and weigh around 100 grams. While still completely dependent on their mother, kittens are born at a much more advanced stage than newborn opossums.
Nursing and Weaning
| Opossums | Kittens |
| Nurse for 2-3 months in mother’s pouch | Nurse for 6-8 weeks |
| Weaned at 3.5 months old | Weaned at 8 weeks old |
The extended developmental period for opossums means they nurse for a much longer time than kittens. Kittens nurse frequently but for under 2 months. Opossums nurse constantly while attached inside the mother’s pouch.
So even though opossums give birth to many more babies per litter, cat mothers end up investing just as many resources into nourishing their young.
Behavior
Social Structures
Opossums are generally solitary creatures that prefer to live alone. They are not territorial and have large overlapping home ranges. Males will temporarily pair up with females during breeding season, but then go their separate ways.
Baby opossums, called joeys, live in their mother’s pouch for 2-3 months before venturing out on their own around 4 months old.
In contrast, cats are more social than opossums. While they can survive independently, domestic cats will form social groups and colonies if living in the same home or area. Feral cats will form large colonies with complex social structures and shared nursing responsibilities.
Pet cats are less extreme but do seem to enjoy having feline company in the home.
Communication
Opossums communicate through vocalizations like hissing, growling or screeching when threatened. They also communicate through scent markings from glands near their eyes and base of their tails. Body language like bearing teeth or wide-eyed staring conveys messages too.
Cats also use vocalization like meowing, purring, growling or hissing to communicate a range of messages from contentment to alarm. They have scent glands around their face and paws to mark territory. Subtle body language with their ears, whiskers and tail helps convey mood and intent.
Hunting and Foraging
As omnivores, opossums are opportunistic scavengers with a varied diet of fruits, plants, insects, snails, slugs, birds, eggs, etc. They have 50 sharp teeth adapted for eating any food sources they come across while wandering 2-3 miles each night.
Opossums help control snail, slug and tick populations.
Cats are obligate carnivores, meaning they depend exclusively on a diet of meat. They are prolific hunters, using their sharp claws and teeth to catch and kill small mammals and birds. Their night vision, stealthy walk and lightning quick reflexes make cats lethal hunters.
Outdoor cats can decimate local bird populations.
Defensive Strategies
Opossums are renowned for “playing possum” or pretending to be dead when extremely frightened. They flop on their side, bare their teeth, drool and exude a foul scent from their anal glands to appear lifeless. This physiological response can last for hours until the danger passes.
When threatened, cats use defensive postures like arching their backs, raising their fur, swishing their tails and standing sideways to appear bigger. They may also vocalize with hissing and growling. If attacked, cats will bite and scratch ferociously with claws and teeth.
Their flexible bodies and quick reflexes make cats formidable fighters.
Habitat and Range
Climate Adaptability
Opossums are incredibly adaptable creatures that can thrive in a variety of climates and environments. They have a high tolerance for extreme temperatures and can survive in climates ranging from below freezing to over 100°F. Their adaptability comes from behavioral and physiological adaptations:
- Opossums lower their body temperature and metabolism during cold weather, entering a torpor-like state to conserve energy.
- They seek shelter in burrows, tree holes, and human structures during extreme weather.
- Their ears function like radiators to help regulate body temperature.
- They groom themselves meticulously to remove any snow or ice buildup on their coat.
Thanks to these adaptations, opossums continue to expand their range northward. While they originally lived in warm, humid climates in Central and South America, they now thrive as far north as southern Ontario and British Columbia in Canada.
Preferred Environments
Opossums prefer living in areas that provide adequate food sources, shelter, and nesting sites. They are habitat generalists that can make their home in a variety of environments, including:
- Woodlands – Opossums particularly like hardwood forests with streams, swamps, and lakes. They den inside tree cavities.
- Rural areas – Barns, woodpiles, brush piles, and rock walls provide shelter. They eat pet food, raid chicken coops, garbage cans.
- Suburban neighborhoods – Opossums take refuge under porches and in attics. They ransack gardens and compost piles.
- Urban environments – They inhabit city parks and greenbelts. They den in abandoned buildings, under dumpsters, and highway underpasses.
Opossums prefer areas with water sources, as it provides drinking water and attracts their prey – frogs, crayfish, small mammals and birds. However, they can survive in arid climates by seeking out moist microhabitats.
Urban Adaptability
Opossums are exceptionally adaptable to human-altered environments due to their flexible diet and ability to occupy urban structures. According to research, their urban population densities in some cities now exceed their densities in rural habitats.[1] Key facts about opossums in urban areas:
- Opossums in cities have smaller home ranges (0.01-0.27 km2) compared to rural ones (0.51-2.65 km2).
- Urban opossums have higher survival rates due to milder climates, abundant food sources and shelter.
- They have generalized diets and eat human garbage, pet food, garden vegetables and fallen fruit.
- Opossums use storm drains, sheds, decks, attics and other structures for den sites.
While adaptable, opossums may face dangers in urban areas like getting struck by cars, ingesting toxins, being attacked by dogs or cats, and being trapped and relocated. Overall, their flexible behavior allows opossums to thrive alongside humans.
Diet and Digestion
Primary Food Sources
Opossums are omnivorous animals with a diverse diet including insects, frogs, plants, fruits, nuts, seeds, mice and eggs. They have a flexible diet and eat anything they can find or catch. Cats on the other hand are obligate carnivores, which means their diet requires nutrients found only in animal flesh.
Cats primarily eat rodents, birds, fish, and sometimes insects. While opossums will eat plant matter, cats cannot properly digest plants and would
Unique Adaptations
Opossums have a super fast metabolism that allows them to clean bones of meat in just 17 hours. They also have a lower than average body temperature compared to other mammals (94-97°F), which researchers think helps their immune system.
Cats also have a fast metabolism and unique adaptations like rough papillae on their tongues for scraping meat off bones. While opossums eat such a wide variety, cats have highly specialized teeth like canines for gripping prey and carnassial teeth that act like scissors to slice meat.
So each animal’s anatomy complements its dietary needs.
Conclusion
While they may look vaguely similar at first glance, opossums and cats have major biological and behavioral differences when it comes to their reproduction, development, diet, habitat preferences, and more. Clearly, it would be a mistake to confuse these two unusual yet common mammals!
Now that you know all about the unique adaptations of opossums and cats, you can impress your friends with your knowledge. You’ll also be better prepared if you ever have a run-in with one of these animals in the wild.
And if it just so happens to be an opossum trying to pass itself off as a cat, you’ll be able to set the record straight!
