Rat Opossum

What are the dietary habits and behaviors of rat opossums?

Rat opossums (family Caenolestidae) are a group of six species of South American marsupials that exhibit specific nocturnal and terrestrial behaviors. While they are capable of climbing, they are primarily ground-dwelling animals that create runways along the forest floor, often utilizing fallen logs, tree roots, and moss-covered rocks for navigation and shelter.¹

Regarding their diet, rat opossums are opportunistic feeders that consume a variety of food sources, including:

• Insects
• Small vertebrates
• Fruit
• Other vegetation¹

These animals are distinct from the more widely known opossums of the family Didelphidae, notably because they are pouchless and possess long, forward-projecting lower incisors. They inhabit moist environments, ranging from the cloud forests of the Andes Mountains to the temperate rainforests of south-central Chile.¹

How have rat opossums been represented in various cultures and folklore?

The available scientific literature does not contain information regarding the representation of rat opossums in cultural traditions or folklore. While other members of the order Didelphimorphia—specifically the Virginia opossum—have been the subject of various myths and folk expressions, such as the belief that they give birth through their noses, these accounts are specific to those species and do not extend to the family Caenolestidae.¹²

Rat opossums are elusive, nocturnal, and pouchless marsupials primarily found in the remote, moist forests of the Andes Mountains and south-central Chile, which may contribute to their lack of prominence in traditional folklore compared to more visible or widely distributed animals.¹

Are there any endangered species of rat opossums, and what conservation efforts are in place?

What are some common misconceptions about rat opossums?

A common misconception regarding rat opossums (family Caenolestidae) is that they possess the same physical traits or behaviors as the more familiar opossums of the family Didelphidae. Because they share the name “opossum,” people often mistakenly assume they are closely related or share identical biological features, such as the presence of a pouch or an opposable thumb.¹

In reality, there are several distinct differences:

• Pouchless Anatomy: Unlike many other marsupials, rat opossums are pouchless.¹
• Lack of Opposable Thumbs: While other American opossums have an opposable big toe on their hind feet used for grasping, the rat opossum’s big toe lacks both a claw and a nail and cannot be used to grasp objects.¹
• Distinct Physical Appearance: Rat opossums are named for their size and general appearance, which resembles that of a shrew or rat, featuring a long, narrow muzzle and greatly enlarged lower anterior incisors that project forward.¹

Additionally, folklore surrounding the Virginia opossum—such as the myth that they give birth through their noses—is often incorrectly attributed to other marsupials, including rat opossums, despite having no basis in the biology of the Caenolestidae family.²