Rat vs. Opossum: What Are the Differences?

Rats and opossums are common in many parts of the United States. While both creatures may look like rodents, only the rat belongs to the order Rodentia. Today, we will explore the differences between the world’s most famous rodent and North America’s only marsupial. Keep reading to learn more about these animals and find out what sets them apart.

Comparing a Rat and an Opossum

The 6 Main Differences Between a Rat and an Opossum

There are over 50 rat species and over 120 opossum species, but the ones that most people in the U.S. are familiar with are the black rat (Rattus rattus), brown rat (Rattus norvegicus), and the Virginia opossum (Didelphis virginiana). There are six main differences between these animals, including size, appearance, distribution, habitat, diet, and their relationship with humans. Take an in-depth look at each of these differences in the following sections.

Size

Brown rats are large rodents, but they are not nearly as large as opossums. Most brown rats grow to between 15-18 inches long including the tail. They weigh 5-18 ounces, with the largest individuals living in urban areas or in captivity as domestic pets. Black rats are smaller and less common. They measure 13-18 inches with the tail included and weigh 4-12 ounces.

Opossums vary in size, mostly depending on their habitat. They measure 24-36 inches long, including the tail. They weigh 4-12 pounds, with the larger individuals living further north. Smaller opossums live in the tropics.

Physical Appearance

Common rats are some of the most identifiable animals in the world. They are generally slender and appropriately rodent-like in appearance. Brown rats have dark brown or gray fur, while black rats are usually only black. Both have pointed faces, hairless tails, pink ears, and pink feet. Fancy rats are domesticated brown rats bred for various colorations, including white, silver, piebald, and more.

Opossums are also familiar to many people. They generally have grayish fur, although some have brown or white speckles. Their ears are typically dark, and their pointed faces are stark white — a feature that can be quite startling at night if you unexpectedly encounter one. Opossums have hairless, prehensile tails, which they can control and use as an appendage.

Distribution

The rat is one of the most widely distributed animals in the entire world, mostly due to humans. The only place they do not inhabit is Antarctica. As a general rule, if there are human establishments, rats most likely have a permanent presence in or near those dwellings.

The Virginia opossum 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 do not live in desert regions or high mountain states.

Habitat

Rats are extremely adaptable and can live in nearly any environment, provided there is food and protection from the elements. They live in urban areas, as well as in fields, forests, and other natural habitats. In the wild, they generally prefer wet environments like riverbanks and shorelines. In urban environments, brown rats are often found in sewers, subways, and other dark places created by humans. Brown rats prefer to live near the ground, whereas black rats prefer higher places.

Opossums are semi-arboreal and usually prefer forests and open woods, where they can den in tree cavities and hollow logs. However, they have also adapted to other environments. They have adapted to live near humans and can be found in urban, suburban, and agricultural areas. They also favor wet areas such as marshes, swamps, and river bottoms.

Diet

Famously, rats are some of the least picky eaters around. They are omnivorous and will eat nearly anything digestible. Additionally, they are known to eat things they are not supposed to, including foam, insulation, and even plaster.

Opossums are also efficient omnivores and scavengers that will eat almost anything. Some of the preferred foods for the opossum include plants, fruit, insects, and small animals. Opossums will even eat garbage and carrion.

Relationship with Humans

In the world of pests, rats are probably the most famous and the most reviled. Their fleas are notorious carriers of diseases, including the Bubonic Plague, rat-bite fever, and more. Billions of dollars are spent each year to remove rats from areas where they have become deeply embedded. Rats have been introduced by humans all over the world and wreak havoc on 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 sometimes considered pests because they may seek shelter in human structures and get into trash bags. There is also a misconception that they carry rabies, but their lower body temperature and immune resistance make this very unlikely. Opossums are considered an important part of the ecosystem because they help with seed dispersal, pest control, and serve as natural scavengers by consuming dead animal matter.