Animals Wildlife 11 Things You Didn't Know About Opossums By Melissa Breyer Editorial Director Hunter College F.I.T., State University of New York Cornell University Melissa Breyer is Treehugger’s editorial director. She is a sustainability expert and author whose work has been published by the New York Times and National Geographic, among others. our editorial process Melissa Breyer Updated May 04, 2020 Photo: Lisa Hagan/Shutterstock Share Twitter Pinterest Email Animals Wildlife Pets Animal Rights Endangered Species Pity the poor opossum. The oft-maligned marsupial definitely suffers from an image problem — it is frequently perceived more as a giant, dirty, scavenging rat rather than a cute creature of the wild. But whether you love them or hate them, North America’s only marsupial has a set of unique characteristics that might transform aversion into affection. But first, the burning question: Is it opossum or possum? In 1608, Capt. John Smith coined the word opossum from the word "opassum," the Algonquian term meaning "white animal." In his notes, the captain wrote: "An Opassom hath an head like a Swine, and a taile like a Rat, and is of the bignes of a Cat. Under her belly she hath a bagge, wherein shee lodgeth, carrieth, and sucketh her young." No one is quite sure how the opossum’s “o” was dropped, but it appeared in print as "possum" as early as 1613, and remains the colloquial term in many regions of the country. However, there are true possums – just not in the North American neck of the woods. Possums include any of several species (from the family Phalangeridae) of nocturnal, arboreal marsupials of Australia and New Guinea, and were mistakenly named in the 18th century when the naturalist from Capt. James Cook’s expedition wrongly called them possums after their North American cousins. Nonetheless, it's the Australian ones that hold the true scientific title of "possum" now. 1. Natural Immunity Opossums are mostly immune to rabies, and in fact, they are eight times less likely to carry rabies compared to wild dogs. 2. Poison Control Opossums have superpowers against snakes. They have partial or total immunity to the venom produced by rattlesnakes, cottonmouths and other pit vipers. 3. Omnivores Galore Opossums are smart and will remember where they traveled to scavenge for food, which includes everything from insects and rodents to table scraps. Lisa Hagan/Shutterstock Their normal diet consists of carrion, rodents, insects, snails, slugs, birds, eggs, frogs, plants, fruits and grains. They also eat human food, table scraps, dog food and cat food. They have an unusually high need for calcium, which incites them to eat the skeletons of rodents and roadkill they consume. They're the sanitation workers of the wild. 4. Smart Critters Although many people think opossums are not the sharpest knives in the drawer, there are several areas of intelligence in which they soar. For one, they have a remarkable ability to find food and to remember where it is. When tested for the ability to remember where food is, opossums scored better than rats, rabbits, cats, dogs ... but not as well as humans. They also can find their way through a maze more quickly than rats and cats. 5. Pest Control Since their diet allows them to indulge on snails, slugs and beetles, they are a welcome addition to the garden. Opossums also keep rats and cockroaches at bay by competing with them for food. In fact, it’s common for opossums to kill cockroaches and rats if they find them in their territory. 6. All Thumbs The opossum has opposable "thumbs." The opossum's "thumbs" (called halux) are on its rear feet (so, technically they're toes), and abet the opossum’s formidable climbing skills. Primates and opossums are the only mammals with opposable first toes. 7. Impressive Tails The opossum can hang by its tail and use it for grasping things. Jay Ondreicka/Shutterstock They have prehensile tails which are adapted for grasping and wrapping around things like tree limbs. The opossum can hang from its tail for short periods of time, but the creature doesn’t sleep hanging from its tail, as some people think. Opossums have been observed carrying bundles of grasses and other materials by looping their tail around them; this conscious control leads many to consider the tail as a fifth appendage, like a hand. 8. Good Pupils The eyes of the opossum appear black, but what we are seeing are strongly dilated pupil; there is iris around them, it’s just mostly out of sight. The giant pupils are thought to be an adaptation to their nocturnal habits. 9. Smile The mouth of an opossum holds an impressive 50 teeth. 10. Natural Defenses When threatened, opossums run, growl, belch, urinate and defecate. And when all else fails, they “play ‘possum" and act as if they are dead. It is an involuntary response (like fainting) rather than a conscious act. They roll over, become stiff, close their eyes (or stare off into space) and bare their teeth as saliva foams around the mouth and a foul-smelling fluid is secreted from glands. The catatonic state can last for up to four hours, and has proven effective as a deterrent to predators looking for a hot meal. 11. They Love Water Most opossums gravitate toward living in areas with reliable water access, despite having the ability to go months without drinking some due to their diet. In addition, they are actually quite proficient swimmers. They enjoy it so much, that they can even get worn out and stranded, like the little guy in the video below. A chef in Michigan found this opossum in the White Lake Channel early one morning. He had worn himself out by challenging the high waters at dawn. Even the best swimmers can overestimate their ability, opossum or not. And, finally, a bonus for the Scrabble players: Male opossums are called jacks and females are called jills. The young are referred to as joeys, just like their Australian cousins, and a group of opossums is called a passel.