| 1 | Fiji: banded sea krait |
Maximum length: 152.5cm.
Fiji was randomly selected as the first member of this list due to being a remote island paradise. You’d expect this exotic country to be a vast kaleidoscope of giant pythons and multicoloured, stealthy vipers plotting to destroy you, but surprisingly, the country has only a handful of native snakes.
The deadliest one is relatively friendly to humans. It’s called the yellow-lipped sea krait, or the banded sea krait, and occurs across Oceania, from peninsular Malaysia to Samoa. It lives on coral reefs and rocky shores, and has a flattened tail which allows it to effortlessly paddle around.
Unlike most sea snakes, adults spend around 50% of their lives on land, although compared to when in water, their speed is slashed by 80%. The banded sea krait’s favourite food is eels, such as conger or moray eels, with a side helping of small fish. In fact, the banded sea krait can swallow an eel twice its own size. Afterwards, the snake can barely swim, and spends days lying on sandy beaches digesting.
Thankfully, this species only rarely attacks humans. Fishermen are most at risk; they’ve been known to accidentally haul up banded sea kraits in their nets, and get bitten when sifting through their catches.
On average, banded sea kraits bite only one human per year, and nobody has died in living memory. However, their venom is extremely powerful, perhaps 10 times deadlier than the average rattlesnake. Each snake produces 10-15mg of venom, and only a fraction of that is needed to end your life.
An old myth has spread around Fiji that banded sea kraits are harmless to humans because their jaws don’t open widely enough, but this is false. Don’t get lulled into a false sense of security!
Nevertheless, the banded sea krait is a mainly docile and non-aggressive species. Fiji might be a nice island to retire to if you’re constantly paranoid about snakes.
| 2 | Argentina: painted lancehead |
Maximum length: 110cm.
Argentina is a country of many extremes. In the far south, it’s like a western European country transplanted halfway across the world, whereas in the north, it’s a humid snakefest like any South American country.
Northeast Argentina sees the most snake bites, with 96.6% coming from the Bothrops pitviper genus, according to a study which examined data from 1978 to 1998. The most bite-happy species of all is Bothrops diporus, AKA the painted lancehead. This species has very few neurotoxins in its venom, yet it covers almost every other lethal possibility. A painted lancehead bite is highly haemotoxic, proteolytic, and myotoxic, meaning that it assaults muscle tissue cells.
Attempting to kill this snake will make it extremely angry (not surprisingly really). Your advice is simple: do nothing to agitate this viper. Make sure that it doesn’t notice you if possible. If you’re strolling past, then keep going, unless it’s blocking the path, in which case you should turn around 180 degrees. If the viper is slithering past as you sit on a picnic bench, freeze still and let it slither on.
Painted lanceheads are confirmed to eat other snakes as well, munching on their fellow kind, including the likes of chaco sipo snakes (Chironius maculoventris). The main cause of death with this species is kidney failure. Its bite covers virtually all local symptoms imaginable, including swelling, intense pain, blistering, necrosis and haemorrhage.
Despite most of Argentina running as fast as possible from this snake, there are still dedicated keepers who think they’re adorable. Painted lanceheads are relatively small, at 60-70cm for males, and females reaching 110cm.
| 3 | USA: eastern diamondback rattlesnake |
Maximum length: 251.5cm.
The longest rattlesnake in the USA when judged by record length, and indeed the world. Also the heaviest snake in the USA, although not the longest, as the gopher snake takes that crown. Yet another US record is the eastern diamondback’s 1 inch fangs, which are the longest in proportion to its body of any rattlesnake species.
This species was first discovered in 1799, and since then, there’s been a constant debate over whether this or the western diamondback causes the most annual deaths. The longest eastern diamondback ever recorded measured 251.5cm, and inevitably, there’s rumours of even longer individuals out there. This snake lives in sandy woodlands and coastal scrubs of the US southeast, particularly Florida and Alabama.
Usually, eastern diamondback rattlesnakes retreat from humans, but when threatened (or perhaps bored), they can spring at you like a jack-in-the-box being unloaded. Their venom is a lethal soup of 95 different proteins and enzymes. Their fangs are sharp, curved, and have hinges which fold within the mouth when not in use.
Life as an eastern diamondback is pretty sweet; they have powerful swimming abilities, infrared-sensing powers, and keen night vision. All of this makes them a deadly predator, despite not actively seeking out humans. Their personalities are particularly unpredictable, as while many snakes rattle their tails as their traditional warning bell at around 25 feet away, other snakes will wait until you’re much closer.
| 4 | England: adder |
Maximum length: 93.5cm.
The best that England can do is the 60cm long, brown and beige zig-zagged adder, a snake that hasn’t killed anyone on British soil for 50 years.
The adder (Vipera berus) is the only venomous snake in the UK, and one of only three native snake species, alongside the pond-loving grass snake and the rare smooth snake. Adders are found in heathland and woodlands, and hibernate for several months during winter. Bites are most common in July and August, and mostly happen when curious people foolishly pick them up or bend down to say hello.
The adder has something of a taste for humans, biting 50-100 people yearly, in addition to 50-100 dogs, but its venom is relatively weak. If the common European adder sinks its teeth into your arm, then the initial effects can appear within the first few minutes, or up to a full hour later.
You’ll probably experience nausea, vomiting, swollen lips and itchy skin. You might get mentally confused, dizzy or disorientated. You might even die. Adders have only killed 14 people in England since 1876, and nobody since 1975, but a few relatively recent patients were clinging onto life by their fingertips.
One third of adder bites are dry bites where the snake doesn’t inject any venom at all, just two painful puncture marks. Pointlessly, the NHS lists “anxiety” as a symptom of a dry bite – what are you going to do, pat the adder on the head affectionately as it bites your arm?
| 5 | Thailand: blue krait |
Maximum length: 160cm.
This is the snake which doesn’t know its own strength. Its venom is among the deadliest, most toxic and corrosive in the whole world, yet the blue krait is surprisingly timid.
Malaysian blue kraits (Bungarus candidus) are found not only in Malaysia, but also Thailand, Vietnam, Cambodia and Java. They tend to congregate near dampness and water, appearing near ponds, rivers and lakes, including near thriving villages. The blue krait also enjoys fields, holes and buildings, but one thing they don’t enjoy is sunshine, as this species is purely nocturnal.
The blue krait’s menu consists mainly of other snakes, including members of its own species. The blue krait boasts a venom 16 times more powerful than that of a cobra, with the one caveat of a relatively low yield. Only 10mg is released in a bite, compared to 150mg for the average Russell’s viper, yet the venom is powerfully neurotoxic, and small dosages are easily enough to kill.
The first symptoms of a blue krait bite include nausea and vomiting. Soon after, muscle paralysis kicks in, followed by a last gasp of massively overexcited muscle spasms, cramps and tremors.
The next stage is complete and total paralysis, and finally, respiratory failure. This is accompanied by a helping of madness, for the venom of this species alters your mind, removing your ability to think clearly. The last thing you want is to be attacked by a blue krait with nobody around to assist you.
What’s strange is that unlike the painted lancehead, a blue krait bite is reportedly painless. This species is relatively timid, and tends to flee from humans and slither away into the undergrowth. That said, do not touch a Malaysian blue krait in any circumstances.
| 6 | Costa Rica: fer-de-lance |
Maximum length: 250.1cm.
The fer-de-lance (Bothrops asper) is a notorious Central American species, which is responsible for 42-46% of snakebites in Costa Rica at the minimum, despite the country hosting 15-20 pitvipers and many more coral snakes. Life is good as a fer-de-lance, with a wide menu that includes geckos, opossums, rabbits, and even the occasional crayfish.
When it comes to humans, the fer-de-lance combines three deadly factors. Firstly, this species has absolutely no fear of human settlements. Banana farms are particular havens for this species, because they’re so packed with tasty rats.
Secondly, the fer-de-lance has an immensely haemotoxic venom, with a particularly powerful set of anticoagulants. Around the bite, you can expect swelling, pain, necrosis. Around your body, you can expect abdominal pain, dizziness, headaches, collapses, and a 20% chance of death if you fail to take the antivenom.
The final factor which makes the fer-de-lance so deadly is its nervous disposition. This species is particularly unpredictable. A cornered fer-de-lance might decide to flee and snack on a nice rodent for tea instead, but alternatively, it might decide to spring randomly towards your face.
This snake is good at pouncing as well, requiring no coil to spring from. When the fer-de-lance does attack, it often attacks repeatedly. The average Joe of this species measures 120-180cm, but the all-time record was a stonking 250.1cm, and there’s always a possibility of this being broken.
Bothrops asper also rules the Venezuelan state of Lara, causing 78% of all snakebite fatalities, and the Colombian regions of Antioquia and Chocó, causing 50-70% of total snakebites.
| 7 | Saudi Arabia: puff adder |
Maximum length: 191cm.
The puff adder (Bitis arietans) is a thick, 1 metre snake which ranks as the most widespread venomous snake in sub-Saharan Africa. However, they also have an overseas outpost in Saudi Arabia (plus Yemen), and in this sun-baked desert kingdom, they’re easily the deadliest snake.
The puff adder can release 150-250mg of venom in a single bite, with a record of 750mg. A serious injection of venom has a 50% mortality rate, while a standard bite gives you a 15% risk of death (without antivenom). Juveniles are deadly as well, and some victims have even died within one day. The puff adder’s venom is so necrotic that the flesh surrounding the bite mark can rot away down to the bone.
Puff adders are extremely fast when striking, as their teeth can move from the desert floor to your arm in just 0.25 seconds. Ordinarily, they’re relatively slow and sluggish, but when threatened, the puff adder accelerates rapidly.
Its beige-black camouflage is legendary, and that’s partly why this species attacks so many people. The puff adder’s fleeing instincts are lower than usual because they’re so used to being hidden, and consequently, they encounter humans frequently.
Saudi Arabia has 50 different snake species, including the Arabia horned viper and diadem snake, but the puff adder is the one which haunts people’s dreams.
| 8 | Cyprus: Levantine viper |
Maximum length: 230cm.
The island of Cyprus has 14 different snakes in total, including 3 venomous snakes. The Montpellier snake and European catsnake pose no threat to human beings whatsoever, due to their backwards-tilted fangs which are unable to sink into human flesh properly. Instead, the deadliest species is the common Levantine viper (Macrovipera lebetinus), which isn’t even close to endangered.
This species is found from Iran to Greece to Cyprus. It posses 1cm long, hinged fangs which slot neatly into the roof of its mouth, and are perfectly angled to sink into your arm. Unlike with Thailand’s blue krait, the Levantine viper has an extremely painful bite, instantly alerting you to the threat.
The Levantine viper is the only snake on Cyprus which is capable of killing a human. Their usual habitats are rocky areas, grassy meadows, and plains without trees. However, they love water, and have a tendency to end up in people’s backgarden swimming pools.
Fortunately, Levantine vipers rarely kill, but serious cases are relatively common. In 2017, a 55 year old man was hospitalised in a critical condition after being bitten, while in 2004, a 4-year old boy almost died after picking up a Levantine viper and being bitten.
Within minutes, the boy’s eyes were rolling as he had a cardiac arrest, and he was actually clinically dead as the ambulance transported him away. The boy’s mother was asked to describe the snake at the hospital, and she recalled a look of dread that appeared on the doctors’ faces. Soon though, the boy was revived by Cyprian medical expertise, with no lasting consequences.
| 9 | France: asp viper |
Maximum length: 82cm.
The deadliest snake of France pales in comparison to the puff adder, but is still significantly deadlier than England’s adder, boasting a fatality rate of 4% if bites are left untreated.
Around 80% of France is in the grip of this terror, excluding the northern 20%, where the adder takes over instead. Asp vipers (Vipera aspis) are common in grassy meadows, particularly in thick hedges along their borders. They’re relatively short, only occasionally reaching 80cm, but have a thick body, as well as a classically triangular viper head. Virtually all of their diet consists of mammals, particularly voles.
Could you wake up inside the stomach of an asp viper one day? No chance, but their venom is highly toxic. The counterbalance is a small venom yield, of just 4.6mg to 20.1mg per bite. Dry bites are also common, although a second bite, if you fail to take a hint, is more likely to be venomous.
Stage 1 symptoms of this species include local swelling and pain. Stage 2 symptoms include massive swelling, low blood pressure and digestive troubles, while the life-threatening stage 3 involves diarrhoea and catastrophically low blood pressure.
In the Pyrenees, this dangerous viper has been found at altitudes of up to 2100 metres. The asp viper kills its small prey within seconds, and bides its time while its toxins slowly kill larger prey. Asp vipers never eat fish or amphibians, despite commonly being found close to water.
| 10 | Vietnam: Malayan pitviper |
Maximum length: 100cm.
Snakes were the second great enemy faced by Americans in the Vietnam war. A rustle in the jungle undergrowth wasn’t necessarily the Vietcong approaching – it could have been an aggressive Malayan pitviper. This species sticks to the ground rather than branches, and is an infamous inhabitant of woodlands, plantations and other farmlands. Statistics reveal that Malayan pitvipers are the number 1 cause of snakebite in Vietnam, just ahead of the monocled cobra.
This is a cocky snake, which doesn’t even bother to leave the area after injecting venom. They can sit there smugly for hours afterwards, as this is an extremely stationary species. Death is a possibility, and victims can be left with permanently swollen limbs.
Malayan pitvipers are inconsistent in their behaviour to a dangerous extent. One morning, they can be completely calm, before erupting with sudden anger the next day, leaving you with two deep fang marks and painfully erupting blisters. Malayan pitvipers fill a similar niche to copperheads in the USA, with a thick body and orange tint, and a liking for dry, leafy forests.
This species occupies not just Vietnam, but Cambodia and much of Thailand. If a Malayan pitviper bites you on the hand, then the odds of losing a finger are dangerously high. This species is mainly nocturnal, but can also moving during cool, overcast days.