Dec 05 , 2019
Opossums are some of the misunderstood animals north of Mexico. They’re often thought of as dimwitted, dirty creatures whose most impressive trick is acting like roadkill. The truth is just the opposite. Opossums are smarter, cleaner, and beneficial to humans than many other animals you would find in their dwellings. Here are some cool facts about opossums you didn’t know:
- Opossums and Possums aren’t the same animal…in Australia: In North America, “opossum” and “possum” describe the same thing, but in Australia the word “possum” refers to a completely different animal. Possums in the land down under look like a cute cross between a squirrel and a chinchilla.
- They’re the only marsupials found north of Mexico: Marsupials—mammals that carry and nurse their young in pouches—are absent from much of the world. Opossums are the only marsupials in North America. Like other marsupials, mother opossums give birth to tiny, underdeveloped offspring (called joeys) that immediately crawl into a pouch where they live and nurse during their first months of life. Only once they’ve grown big and strong enough do they venture out, transitioning between their mother’s back and the warmth of the pouch until they mature into adults.
- They can’t choose when they play dead: Opossums are infamous for playing dead in front of predators. When the animal experiences intense fear it seizes up and flops to the ground where it can remain for hours staring blankly ahead and sticking out its tongue. It’s an impressive defense mechanism, but they have no control over when they play dead or for how long they do it. The comatose-like state is an involuntary reaction triggered by stress.
- The order helps sells the performance of playing dead: Normally opossums don’t smell (see #5), but when playing dead is necessary they secrete a putrid order from their anus which makes predators like bobcats or foxes look for dinner elsewhere.
- They’re constantly self-grooming: Opossums take cleanliness very seriously. The Washington Department of Fish and Wildlife writes that opossums, like housecats, use their tongue and paws to groom themselves frequently and thoroughly. They largely lack sweat glands, and this behavior is believed to help them cool down. This also has the added effect of rendering them odorless; unless they are trying to repeal predators, that is.
- They slow the spread of Lyme Disease: Unlike other mammals that carry ticks, and therefore spread Lyme Disease, opossums gobble up 90% of ticks that attach to them. According to the National Wildlife Federation, a single opossum consumes 5,000 of the parasites per tick season. That means the more opossums that are in your area, the fewer ticks you’ll encounter.
- Their memories are surprisingly sharp: Opossums have impressive memories—at least when it comes to food. Researchers found that opossums are better at remembering which runway led to a tasty treat than rats, cats, dog, and pigs. They can also recall the smell of toxic substances up to a year after they have been exposed to them.
- They’re immune to most snake venom: While most animals look at a snake and see danger, an opossum sees its next meal. The animals are immune to the venom of nearly every type of snake found in their native range; the one exception being the coral snake. Opossums take advantage of this adaptation by chowing down on snakes on a regular basis.
- They almost never get rabies: While opossums aren’t totally immune to rabies (a few cases have been documented), finding a specimen with the disease is extremely unlikely. Marsupials have a lower body temperature than the other mammals which dominate North America. In other words, their bodies don’t provide a suitable environment for the virus.
- Their tail acts as a fifth appendage: Opossums are one of the handful of animals with prehensile tails—tails which have adapted to hold or manipulate objects. These appendages are sometimes used as an extra arm. They can carry grass and leaves for building nests or grip the sides of trees or branches to provide extra stability while climbing. Opossums are often depicted hanging upside down or sleeping this way, but this is actually a myth. Their tails are only strong enough to hold them for a short amount of time.
- Their eyes aren’t totally black: Opossums eyes do have whites and irises, but because their pupils are so large, their eyes appear completely black from a distance. The exaggerated pupil dilation is thought to help the nocturnal animals see after the sun goes down.
- They’re social creatures: It was long assumed that opossums like to keep to themselves, but a study published in the journal Biology Letters suggests they have a social side. Researchers at the Federal University of Pernambuco in Recife, Brazil observed some opossums in captivity sharing dens even if they weren’t mates. In one case, 13 white-eared opossums of various age groups were cohabiting the same space. The scientists suspect that male and female opossums living in the wild may even build nests together as a way to trigger the female’s reproductive hormones.
- Their reproductive systems are complicated: Female opossums have two vaginal tracks and two uteri, and males in turn have a bifurcated penis. This is fairly typical for marsupials, but when European colonizers first landed in North America centuries ago, they didn’t know what to make of the confusing genitalia. One explanation they came up with was that male opossums impregnated females through the nose. HA!