Rat vs Opossum: What Are The Differences?

Written by Colby Maxwell
Published: June 22, 2022
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Rats and opossums are extremely common in many parts of the United States. While both creatures may look like rodents, only the rat is officially recognized as one. Today, we will be exploring the difference between the world’s most famous rodent and North America’s largest marsupial! Let’s discover: Rat vs Opossum; what’s the difference?

Comparing a Rat and an Opossum

Rats and opossums differ in size and habitat.


SizeBrown rat: 16 inches (with tail), 0.5-1 lbs
Black rat: 8 inches, 2.6-8.1 oz
2.5 ft excluding tail. Weighs around 1.7-14 lbs.
AppearanceDark grey, brown, or black. Hairless tail, pointed face, pink feet.Thin fleshy tail, stark-white face, gray bodies, pink feet.
DistributionWorldwide.North and Central America.
HabitatAlmost everywhere.Forests, urban areas, and semi-arid regions.
DietAlmost everything.Omnivorous scavengers.
Relationship with humansWidespread and considered disease-bearing pests.Venom tolerance. Playing dead.

The 6 main differences between a Rat and an Opossum

The main differences between a rat and an opossum are that rats are smaller, live all over the world, and are considered rodent pests in most places. Opossums are larger, only live in the Americas, and aren’t generally considered pests.

Rats and opossums come in a few varieties, but the ones that most people are familiar with are the black and brown rat and the Virginia opossum. Still, most people refer to them as “rats” and “possums,” regardless of their specific species.

Between black and brown rats, brown rats are significantly larger. They are also commonly known as sewer rats, common rats, and street rats and are the ones most people see in large urban areas like the NYC subway system. Opossums are significantly larger than even large brown rats. On average, brown rats weigh less than a pound, while opossums can weigh up to 14 lbs.

Both rats and opossums appear rodent-like, but rats are the only ones that truly are. As such, they have a standard rodent appearance, with fur, pink ears, pink feet, and a hairless tail. Smaller rats and mice can look similar. Opossums are usually gray and black, have stark white faces, pink feet, and a hairless prehensile tail. Additionally, opossums are marsupials and have pouches where they raise their young.

In addition to these differences, let’s cover a few more below, including distribution, habitat, diet, and their relationship with humans.

Rat vs Opossum: Size

Rat vs Opossum
Opossums are much larger than rats, although the brown rat is larger than the black rat.

Heiko Kiera/Shutterstock.com

Brown rats are quite large rodents, but they aren’t nearly as large as opossums. Most brown rats grow to between 0.5 and 1 lbs, with the largest members living in urban areas or in captivity (as domestic pets). Black rats, though not as common, grow between 2.6-8.1 oz.

Opossums are quite variable in their size, mostly depending on their habitat. They measure up to 2.5 feet long. Additionally, they weigh between 1.7 and 14 lbs, with the larger individuals living further north. Smaller opossums live in the tropics.

Rat vs Opossum: Appearance

Rat vs Opossum
Opossums have dark bodies and stark white faces.


Common rats are some of the most identifiable animals in the world. They are generally slender and rodent-like in their appearance. Brown rats come with dark brown or gray fur, and black rats are usually black. Both have hairless tails, pink ears, and pink feet. Fancy rats are domestic brown rats that have been bred to have different colorations, including white, silver, piebald, and more.

Opossums are also well-known to people that happen to live in close proximity to them. They generally have gray bodies, although some have brown or white speckles. Their ears are black, and their faces are stark white, a feature that can be quite frightening at night when you stumble into one unexpectantly. Opossums have hairless prehensile tails, meaning they can control them and use them as an appendage.

Rat vs Opossum: Distribution

Rat vs Opossum
Rats live everywhere on earth.


The rat is one of the most widely distributed animals in the entire world, mostly due to humans. As a general rule, if there are human establishments, rats most likely have a permanent presence within or nearby human dwellings.

Opossums exclusively live in the Americas. The Virginia opossum, the one that most are familiar with, only lives in Central and North America. In the United States, opossums can be found along the east coast, in the south, along the west coast, and in the midwest. They generally don’t live in the desert regions or in the high mountain states.

Rat vs Opossum: Habitat

Rat vs Opossum
You can find rats anywhere you can find humans.

iStock.com/Liudmila Chernetska

Rats are extremely adaptable and can live in nearly any environment, provided it has protection from the elements. In the wild, they generally prefer wet environments like riverbanks and shorelines. In urban environments, brown rats are often found in sewers, subways, and around the dark places that humans have created.

Opossums are semi-arboreal and usually prefer regions with trees, although that isn’t always the case. Most of the time, opossums live in or around forested regions. Additionally, they have adapted to live in close proximity to humans and can be found in urban and suburban areas.

Rat vs Opossum: Diet

Rat vs Opossum
Opossums are also omnivorous scavengers.

Famously, rats are some of the least-picky eaters around. They are omnivorous and will eat nearly anything they can get. Even more, they are known to eat things that they aren’t supposed to, including foam, insulation, and even plaster.

Opossums are efficient omnivores that will also eat almost anything. The preferred foods for the opossum include carrion, dead material, fruits, insects, and even small animals.

Rat vs Opossum: Relationship with humans

Rat vs Opossum
Rats are both pests and pets all around the world.

Linda Bestwick/Shutterstock.com

In the world of pests, rats are probably the most famous and the most reviled. They are famously the carriers of diseases, including the Bubonic Plague, rat-bite fever, and more. Billions of dollars a year are spent in order to remove rats from areas they have become deeply embedded. Rats have been introduced by humans all over the world and wreak havoc in native environments. Strangely enough, however, they are also kept as pets. Domestically bred brown rats are known as “fancy rats” and are often sold at pet stores.

Opossums are occasionally considered pests by humans, but only because they occasionally seek shelter in human establishments and can get into trash bags. Other than that, opossums are considered an important part of an ecosystem.

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