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8 Spiny Creatures You Don’t Want to Meet in the Wild

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When you think about it, the human defense system is really lacking. Unlike other animals, we can’t shoot poison out of our body. We don’t have bony armor to hide behind. Our fingernails can’t even be fashioned into a decent claw. Formidable spikes are one of of these crazy, enviable ways animals have to defend themselves against potential predators. 

A few of these spiny, spiky creatures that could poke your eye out in the wild. Here’s a sample of the terrifying moving cacti of the animal kingdom.

1. The short-beaked echidna 

Image Credit: KeresH via Wikimedia Commons // CC BY-SA 3.0

This Australian mammal looks like a giant hedgehog crossed with an anteater and lays eggs, much like a platypus. The average 9-pound echidna is covered in spikes and will curl up in a ball if threatened. One researcher who has spent time with the animals calls them “spiky baby killers” due to the males’ habit of eating their young. 

2. The hairy frog

Image Credit: J. Green via Wikimedia Commons // Public Domain 

Also known as the “horror frog,” this African species pierces its own skin with sharp bones in its toes, turning a normal foot into a terrifying claw. The fist-sized amphibians are hunted as food in their native Cameroon—but only using long spears and machetes that keep them at a distance.

3. The armored rat

A stuffed armored rat. Image Credit: ZeWrestler via Wikimedia Commons // CC BY-SA 3.0

The armored rat is covered in “impressively broad and stiff” spines up to an inch long. A native of South America, it looks exactly like the subway rat of your nightmares.

4. The spined spider

Image Credit: Thomas Shahan via Wikimedia Commons // CC BY 2.0

Micrathena spiders, found in forests, look kind of like a bug that swallowed a jack. The females of the species have pointy, sharp growths extending from their abdomen that make them unappealing to predators. And us. 

5. The Spanish ribbed newt 

Image Credit: David Perez via Wikimedia Commons // CC BY 3.0

When threatened, this amphibian rotates its ribs until they pierce through its skin, creating spiny nodules covered in toxic secretions. This is not the kind of animal you want to sneak up on.

6. Potto

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The potto is a small, nocturnal primate that lives in trees throughout the tropical regions of Africa. They look plenty cuddly from the outside (not unlike a loris), but when attacked, they curl their necks down to reveal protective spines hidden under the skin. 

7. Hatpin urchin 

Image Credit: James St. John via Wikimedia Commons // CC BY 2.0

Do not poke the hatpin urchin, whose needle-like spikes are toxic and can be up to a foot long. Centrostephanus longispinus can be found in the Atlantic Ocean and the Mediterranean [PDF]. The urchins hide in rocky crevices during the day, and come out to forage at night.

8. Thorny dragon 

Image Credit: Christopher Watson via Wikimedia Commons // CC BY-SA 3.0

Also known as the thorny devil, this Australian native is covered with sharp thorns that look like what you would find on a rose stem. The desert lizards are only a few inches long and stick to a diet of a few thousand ants a day, but they look battle-ready at all times. When a predator shows up, thorny dragons puff their bodies up—sticking out their spines—and tuck their heads down to reveal a spiny appendage that looks like a false head, making them hard for a snake to get its mouth around.

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13 Facts About Opossums
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Opossums, which include the roughly 100 species in the order Didelphimorphia, are some of the most misunderstood animals in the Americas. 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 more beneficial to humans than many of their woodland neighbors. Read on for more opossum facts.

1. OPOSSUMS AND POSSUMS AREN’T THE SAME ANIMAL.

In North America, opossum and possum describe the same thing, but in Australia the word possum refers to a completely different animal. Among the most well known of their respective types are the Virginia opossum and the brushtail possum. Both are small to medium sized, omnivorous marsupials, but the similarities end there. The possum looks like a cute cross between a squirrel and a chinchilla and it belongs to a different order than the North American mammal that shares (most of) its name. Despite the potential for confusion, possum is accepted as the shortened version of opossum in this part of the world (and if you see the word possum in this list, you can assume it’s referring to the animal from the Americas).

2. 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, and in Canada and the United States opossums are the sole representatives of the group. Like other marsupials, mother possums 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.

3. THEY CAN’T CHOOSE WHEN THEY PLAY DEAD.

Possum playing dead.
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Perhaps the most famous characteristic of the opossum is its tendency to play dead in front of predators. When the animal experiences intense fear in the face of danger, 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 defensive mechanism, but its effectiveness can’t be chalked up to the possum’s acting skills. Possums 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.

4. AN OFFENSIVE ODOR SELLS THE PERFORMANCE.

A picture of a possum playing dead doesn’t really do it justice. To get the full experience, you need to be standing over to it to smell the putrid odor it emits when pretending to be a corpse. The smelly substance it secretes from its anus is just one more reason for foxes and bobcats to look for their dinner elsewhere.

5. THEY SLOW THE SPREAD OF LYME DISEASE.

Even if possums aren’t the cutest creatures in the forest, they should be a welcome addition to your backyard. Unlike other mammals that carry ticks, and therefore spread Lyme Disease, possums gobble up 90 percent of the ticks that attach to them. According to the National Wildlife Federation, a single possum consumes 5000 of the parasites per tick season. That means the more possums that are in your area, the fewer ticks you’ll encounter.

6. THEIR MEMORIES ARE SURPRISINGLY SHARP.

Possum looking up at table.
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Opossums have impressive memories—at least when it comes to food. Researchers found that possums are better at remembering which runway led to a tasty treat than rats, cats, dogs, and pigs. They can also recall the smell of toxic substances up to a year after trying them.

7. THEY’RE IMMUNE TO MOST SNAKE VENOM.

While most animals look at a snake and see danger, a possum 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. Possums take advantage of this adaptation by chowing down on snakes on a regular basis.

Researchers have been trying to harvest possums’ antivenom powers for decades. A few years ago, a team of scientists made progress on this front when they recreated a peptide found in possums and and found that mice given the peptide and rattlesnake venom were successfully protected from the venom’s harmful effects.

8. THEY ALMOST NEVER GET RABIES.

While possums aren’t totally immune to rabies (a few cases have been documented), finding a specimen with the disease is extremely unlikely. Marsupials like possums have a lower body temperature than the placental mammals that dominate North America—in other words, their bodies don’t provide a suitable environment for the virus.

9. THEIR TAIL ACTS AS A FIFTH APPENDAGE.

Baby opossum hanging from a tree branch by its tail.
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Opossums are one of a handful of animals with prehensile tails. These appendages are sometimes used as an extra arm: They can carry grass and leaves for building nests or grip the sides of trees to provide extra stability while climbing. Baby possums can even use their tails to hang from branches upside down as they’re often depicted doing in cartoons. But it’s a myth that possums sleep this way: Their tails are only strong enough to hold them for a short amount of time.

10. THEY’RE CONSTANTLY SELF-GROOMING.

Thanks to their whole acting-and-smelling-like-a-corpse routine, opossums aren’t known as the most sanitary animals in nature. But they take cleanliness seriously: The Washington Department of Fish and Wildlife writes that possums, like housecats, use their tongue and paws to groom themselves frequently and thoroughly. Possums largely lack sweat glands, and this behavior is believed to help them cool down. It also has the added effect of rendering them odorless (when they’re not secreting stinky predator-repellant, that is).

11. THEIR EYES AREN’T TOTALLY BLACK.

Close-up on opossum's face.
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One of the opossum’s most recognizable features is its pair of opaque eyes. Opossum 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.

12. 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 possums 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 possums living in the wild may even build nests together as a way to trigger the female’s reproductive hormones.

13. THEIR REPRODUCTIVE SYSTEMS ARE COMPLICATED.

The way it gives birth and raises its young isn’t the only thing that’s interesting about the opossum's reproductive life. Females have two vaginal tracts and two uteri, and males in turn have a forked or 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.

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Andreas Trepte via Wikimedia Commons // CC BY-SA 2.5
Climate Change Has Forced Mussels to Toughen Up
Andreas Trepte via Wikimedia Commons // CC BY-SA 2.5
Andreas Trepte via Wikimedia Commons // CC BY-SA 2.5

Researchers writing in the journal Science Advances say blue mussels are rapidly evolving stronger shells to protect themselves against rising acid levels in sea water.

Bivalves like mussels, clams, and oysters aren’t good swimmers, and they don’t have teeth. Their hard shells are often the only things standing between themselves and a sea of dangers.

But even those shells have been threatened lately, as pollution and climate change push the ocean's carbon dioxide to dangerous levels. Too much carbon dioxide interferes with a bivalve’s ability to calcify (or harden) its shell, leaving it completely vulnerable.

A team of German scientists wondered what, if anything, the bivalves were doing to cope. They studied two populations of blue mussels (Mytilus edulis): one in the Baltic Sea, and another in the brackish waters of the North Sea.

The researchers collected water samples and monitored the mussel colonies for three years. They analyzed the chemical content of the water and the mussels’ life cycles—tracking their growth, survival, and death.

The red line across this mussel larva shows the limits of its shell growth. Image credit: Thomsen et al. Sci. Adv. 2017

Analysis of all that data showed that the two groups were living very different lives. The Baltic was rapidly acidifying—but rather than rolling over and dying, Baltic mussels were armoring up. Over several generations, their shells grew harder.

Their cousins living in the relatively stable waters of the North Sea enjoyed a cushier existence. Their shells stayed pretty much the same. That may be the case for now, the researchers say, but it definitely leaves them vulnerable to higher carbon dioxide levels in the future.

Inspiring as the Baltic mussels’ defiance might be, the researchers note that it’s not a short-term solution. Tougher shells didn’t increase the mussels’ survival rate in acidified waters—at least, not yet.

"Future experiments need to be performed over multiple generations," the authors write, "to obtain a detailed understanding of the rate of adaptation and the underlying mechanisms to predict whether adaptation will enable marine organisms to overcome the constraints of ocean acidification."

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