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You probably know that Australia is famous for giant snakes and spooky spiders... but oh... there's SO much more. Join Hank Green as he shows you seven truly terrifying Australian inhabitants that you might not have heard of—and some are downright deadly.

Sydney funnel-web spider photo by Tirin

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Giant centipedes:

Strychnine trees:

Cone snails: [PDF] [PDF]

Gympie Gympies:,-never-forgotten/ [PDF]

Irukandji jellyfish:
Between the funnel web spiders that can hide in your boots and the snakes that can slither into your house, Australia can be a pretty scary place.

Well, you don’t even know the half of it. Because odds are, you’re not going to stumble across an inland taipan or a saltie on your bike ride to work, while you’re relaxing at the beach, or when you’re out hiking with your friends.

And that’s exactly where you’ll find the terrors on this list. Turns out there are plenty of horrifying plants and animals living in Australia, even when the usual suspects are excluded. So we’ve rounded up seven that you might want to keep in mind if you’re going to spend a lot of time down under. ♪.

If you hang out in the suburbs along the coasts of Queensland, New South Wales, or southern. Western Australia during spring, you might meet an Australian magpie. You could be just walking or biking along, minding your own business, when one of these 40 centimeter long black and white birds swoops in out of nowhere.

It might even grab onto your shirt with its sharp claws and start stabbing rapidly at your eyes like a scene from Hitchcock’s The Birds. But this isn’t a movie—this is a real thing that happens, in real life to real people, and it happens a lot. In 2017, there were more than 3200 attacks and 520 injuries from magpies in Australia.

These birds are highly territorial, and their aggressive swoops are their way of defending their chicks. But less than 15% of magpies attack people, usually ones with nests close to cycling paths. And that’s because human attacks are actually a learned behavior—the product of a sharp mind that likely arose because the birds are really social.

Scientists have found that magpies who live in big groups do better on problem solving tests and have more of their eggs hatch, showing that brain power is linked to their reproductive success. And that might be because that brainpower allows them to learn things like how to hurt a human! Magpies can even remember faces and attack the same people over and over again each season—and these are birds that can live for 20 plus years.

So just expect... decades... of this! Human attacks do seem to be on the rise, too, which is probably because they work! People avoid the areas where attacks happen, which reinforces the idea that this behavior lets them raise their chicks in peace.

If you want to try your luck around Australia’s magpies anyway, locals recommend turning a helmet into a porcupine with a bunch of zip ties. Ticks are found all over the world, and they’re not exactly anyone’s favorite animal since the whole thing that they do is attach to your body and suck your blood. But along Australia’s eastern shores, one species of tick—the paralysis tick—can do something much creepier: it can make you allergic to meat.

Like pretty much all ticks, these spider-like creatures leap off blades of grass onto mammals like ourselves in search of a tasty blood meal. They’ll plunge their sharp mouth parts or chelicerae into flesh and inject a concoction that ensures they can slurp up blood without interruption. And that’s where it all goes wrong.

Along with the toxins that prevent blood from clotting, the tick injects a cocktail of other chemicals and anything else hanging out in its saliva. That can include the pathogens behind things like Q fever and an Australian version of typhus. And it also includes neurotoxins, which normally just numb the area, but in extreme cases, can slowly paralyze you completely if the tick isn’t removed.

Hence the name “paralysis tick”. But strangest of all is that this tick’s saliva contains galactose-alpha-1,3-galactose -- a carbohydrate also found in many red meats. Get too many tick bites, and you can become sensitive to this carbohydrate.

And that means you can develop what’s known as tick-induced mammalian meat allergy, even though it extends to all mammal products, including milk. So your time down under could make it so you can never enjoy Aussie cheese fries or a juicy steak from Outback ever again. The giant centipede is so fearsome it’s even known to take on some of Australia's scariest snakes.

These 16 cm long centipedes are found pretty much everywhere Australia but also in parts of the Solomon Islands, New Guinea, Indonesia, Southeast Asia, China and Japan. Like other centipedes, they’ve turned their two front legs into menacing hunting tools called forcipules that not only pack a powerful bite but also inject venom into their victims. That venom contains dozens of toxins, and is so powerful that it can easily bring down small lizard or snake.

It’s not clear what all the different components do, but researchers have found that the venom contains cystatin, a protein which fights against our immune defenses. And it contains glycoside hydrolase, an enzyme which helps it spread throughout the body. Bites from these centipedes aren’t usually lethal to beasts our size, but they do hurt.

A lot. Sometimes for days. And that’s likely due to special pore-forming toxins which mess with neurons and can even kill cells.

The biggest danger, though, is that some venom components are similar to ones in bees and wasps, so people with allergies to those animals can go into anaphylaxis if bitten. Thankfully they’re nocturnal and pretty easy to spot, so bites aren’t too common. But you do want to know they’re there so you can watch out for them!

The strychnine tree found in Australia’s southeastern temperate forests might look pretty harmless with its beautiful, fragrant, white flowers and small, orange-like fruit. But those alluring flowers and appetizing fruit house the dangerous, nitrogen-rich compound that gives the tree its name. Strychnine is an alkaloid like caffeine and nicotine, and it had been used in traditional medicines for centuries.

But it’s also the key ingredient in some kinds of rat poison and many Agatha Christie’s murder mysteries. Strychnine acts on the central nervous system by binding to glycine and acetylcholine receptors, particularly those on motor nerves in the spinal cord. Glycine and acetylcholine calm neurons down, making them harder to trigger.

Since strychnine lessens that calming ability, the neurons fire more easily. Symptoms start with muscle soreness and stiffness, but can escalate quickly to convulsions and seizures. If the toxin affects your heart or lungs, then your odds of survival go down fast.

And you only need to ingest 60 to 100 milligrams of the stuff to meet your unpleasant end—roughly the amount in the seeds from a single fruit. So yeah, you can’t trust Australian trees any more than you can trust Australian animals, apparently. Speaking of pretty things that are way more dangerous than you’d think.

If you’re snorkelling on one Australia’s many beautiful reefs, don’t touch any pretty conical snail shells you see. If you get too close, these predatory snails can spear you with their venomous harpoons! The Queen Victoria Cone is endemic to Australia, meaning its the only place in the world you’ll find these ghastly gastropods.

Although it is similar to the equally-scary and more widespread Geography Cone, which is also found in Australia’s northern waters. Both subdue their prey by stabbing them with venom-delivering, tooth-like things called radulas. Cone snail venoms contain dozens of different conotoxins—short chains of amino acids that can mess with neuronal signaling in different ways, ultimately paralyzing their victims.

Those potent venoms allow these snails—which, as you would expect, aren’t exactly known for their speed—to feed on animals that might otherwise outpace them. Some species even take down fish! If you’re unfortunate enough to tread on one of them, you might just feel a bee-like sting at first.

Then, the stung area may go numb and turn blue due to the lack of blood flow. The limb could become temporarily paralyzed, and you could even experience blurry vision, feel faint or have trouble breathing as the venom spreads. And big geography cones have killed people, though deaths are super rare.

So... maybe think twice before picking up that souvenir from the ocean floor. If you already know not to eat suspicious looking fruit or pick up unknown objects from the sea, great. But to be wracked with agony for months, all you have to do is brush up against the wrong plant on a hike in the tropical forests of northern Australia, particularly the beautiful.

Tablelands near Cairns. The Gympie Gympie tree is infamous for causing some of the most excruciating pains imaginable. One researcher described it as burning like acid while being electrocuted at the same time.

And it packs such a painful punch because its stem, purple raspberry-like fruits, and heart-shaped leaves are all covered with tiny, silica-tipped hairs — the same stuff that makes up quartz. These easily pierce your skin then break open, releasing toxins stored inside. The main pain-inducing compound is a linked bundle of eight amino acids called moroidin—though how it causes such agony is not known.

The hairs are so delicate and fine that your skin can quickly heal over them, trapping them inside you. There, the hairs take years to break down, and every time you move, they can release more of the very stable, very painful chemical. People have reported continuing pains for up to a year after being stung.

What’s more, the Gympie Gympie regularly sheds its hairs, making them airborne where they can drift into your nose and cause nosebleeds. And while, compared to other toxins on this list, moroidin isn’t that deadly, people have died from Gympie Gympie stings—either from shock, or just because the pain became too much to bear. Curiously, some native Aussie animals have learned to tolerate the toxin and can eat the leaves and fruit without having those silica tipped spines explode in their mouth and cause excruciating pain!

No such luck for us though! Last on our list is probably the most terrifying creature Australia has to offer—and I’m counting the snakes and such when I say that. It’s tiny — only about 5 millimeters wide — and practically invisible.

But its stings are so painful, that it feels like your insides are crumbling. The common kingslayer is one of the smallest jellies known to harm people. So far, its range is restricted to northern Queensland, but scientists are concerned that climate change will allow them to move south to Australia’s more popular beaches.

It’s tiny size and colorless body are what make it so dangerous, because it’s hard to see even in daylight, which makes its meter long tentacles that much more difficult to avoid. Unlike most jellyfish that only have stingers or nematocysts on their tentacles, these jellies have them all over their bodies. And when they touch you, they can fire a thin tubule into your skin that injects the animals’ potent venom.

Like other jellies, their stings can burn. But they can also cause Irukandji syndrome, where your body releases dangerous levels of catecholamines. These compounds, like epinephrine, ramp up your sympathetic nervous system, causing rapid heart rate, nausea, and an overall impending sense of doom.

And that sense isn’t necessarily wrong—the jelly was named after Robert King, an American tourist who died from its sting. Luckily, stings are rarely fatal, as doctors are usually able to manage the syndrome’s more dangerous symptoms. In fact, before you cross Australia off your list of desirable holiday destinations, you can take solace in the fact that none of these horrifying things actually cause that many deaths.

Neither do Australia’s snakes or spiders, for that matter. You’re much more likely to die from falling off a horse or being kicked by a cow than you are being pecked, bitten, or stung by one of the terrors on this list. Will it hurt?

Will it be excruciatingly painful? Absolutely. But you'll probably survive!

And now that you know what to look out for, you’ll be even better at avoiding them! Thanks for watching this episode of SciShow. If you liked this list of horrifying living things, you might like our episode on 8 creepy animals that are actually harmless. ♪.