Deadliest snakes in the world

 List of the most venomous snakes on the planet

Snake bites constitute a major cause of animal-related deaths, with the WHO describing it as a “a neglected public health issue”. Venomous snakes bite about 5.4 million people every year, resulting in between 81,000 and 138,000 deaths, according to the World Health Organization. This makes snakes pretty high up on the list of deadly animals with humans. That is not to say all snakes are deadly and dangerous, however. Of the around 3,900 species only 725 are venomous, and of these only 250 are able to kill a human with one bite. It is possible for non-venomous snakes to kill humans, but this is excessively rare (around one or two deaths per year), and mostly limited to interactions with pet constrictor snakes like pythons.

An encounter with one of these venomous snakes could cost you your life. King cobras are the longest venomous snakes on Earth. Largest snake species in the world discovered is in Amazon rainforest. They hiss, they slither and unfortunately for humans and unsuspecting prey, they bite. Their secret weapon is of course venom, which contains toxic substances produced in a modified salivary gland which the animal then injects into prey using their fangs. Venom first evolved around 60 million years ago, after large constrictors like boa constrictors and pythons diverged from other snakes. These non-venomous ancestors likely already made mildly toxic proteins in their secretory glands, which gave them a huge advantage when capturing prey. Through millions of years, more and more toxins started to get incorporated into the venom.

Despite the wide-array of snakes, venoms are mostly composed of four types of compounds: phospholipases, serine proteases, metalloproteases, and three-finger toxins.  Each type has unique physiological effects. For instance, three-finger toxins prevent nerve transmission, while phospholipases and metalloproteases may digest tissue and cause swelling, tissue death and massive bleeding. And any given snake's venom may contain multiple compounds, each with their own deadly effects. Snake venom cure is developed fake blood vessels to help reduce deadly bites. Venomous snakes on the other hand are responsible for a great many deaths, as well as injuries like tissue necrosis resulting in amputation. Snake bites occur most commonly and severely in developing countries where antivenom is less easily available, especially in rural areas. Following is our list of the deadliest snakes with bites that can kill.

Saw-scaled viper (Echis carinatus)

When discussing venomous snakes, deadly could mean one of two things. It could either mean the snake that kills the most people, or it could mean the most highly toxic snake, the one that is most likely to kill you if it bites you. These can be very different things, as those with the most potent venom are not necessarily the most common, commonly in contact with humans, aggressive or bold. The snake that is thought to kill the most people annually, and therefore the world's deadliest snake, is the saw-scaled viper, a particularly aggressive species found in the Middle East and central Asia. It is this aggression, as well as its presence in densely populated areas, which determines its deadliness. 

A saw-scaled viper, with brown, beige and white patterning, camouflages itself among dirt and grass. The saw-scaled viper (Echis carinatus) is the smallest member of the "Big Four" in India, along with Russell's viper, the common krait (Bungarus caeruleus) and the Indian cobra (Naja naja), thought to be responsible for the most bites and related deaths in the country. Along with their fellow vipers, the Russel's viper and the pit viper, these nondescript little reptiles may be responsible for about 58,000 deaths a year. Rather than the stereotypical "hissing" sound attributed to snakes, this viper starts "sizzling" by rubbing together special serrated scales when threatened. Once bitten by this viper, a person will have localized swelling and pain in the area, followed by potential hemorrhage. Since the venom messes with a person's ability to clot blood, it can lead to internal bleeding and ultimately acute kidney failure, according to the research. Hydration and antivenom (there are nine types of antivenom for this snake) should be administered within hours of the bite for a person to survive, research says.

Inland taipan (Oxyuranus microlepidotus)

On the other hand, when it comes to the most toxic, the inland taipan takes the prize. Endemic to semi-arid regions of central east Australia this snake is a specialist hunter of mammals (primarily rodents), so has evolved a potent venom adapted to kill warm-blooded animals. This venom is by far the most toxic of any snake. It is estimated that just one bite contains enough lethality to kill at least 100 adult humans! Compared to the saw-scaled viper, however, it doesn't actually kill very many at all, with only a few recorded fatalities ever. This is primarily because it rarely comes into contact with humans, living in remote places and spending a lot of its time underground. We named the inland tapia as one of the world's most venomous animals. 

Inland taipans are the deadliest snakes in the world. The inland taipan is one of the most venomous snakes, meaning just a teensy bit of its venom can kill prey (or human victims). They live tucked away in the clay crevices of Queensland and South Australia's floodplains, often within the pre-dug burrows of other animals. Living in more remote locations than the coastal taipan, the inland taipan rarely comes into contact with humans. When the taipan does feel threatened, the snake coils its body into a tight S-shape before darting out in one quick bite or multiple bites. A main ingredient of this venom, which sets it apart from other species, is the hyaluronidase enzyme. According to Toxins journal (Novel Strategies for the Diagnosis and Treatment of Snakebites), this enzyme increases the absorption rate of the toxins throughout the victim's body.

Black mamba (Dendroaspis polylepis)

Another snake with extremely potent venom is the black mamba. This snake, found in sub-Saharan Africa, is one of the most feared of all. Unlike the relatively docile inland taipan, the black mamba is known to be particularly aggressive. Although it does not seek out humans, when cornered or threatened it will rear up and strike repeatedly. This is a situation you definitely do not want to be in, as the black mamba is also renowned for the speed with which it can kill. Neurological symptoms such as slurred speech and muscle twitches can start to become evident within 10 minutes of the bite and death can result within as little as half an hour. Untreated bites have a terrifying 100% mortality rate, making the speed of treatment and availability of antivenom crucial.

Black mambas are Africa's deadliest snakes. Black mambas are some of the scariest snakes on the planet. Named for the dark, inky colour inside of their mouths, black mambas are actually brownish in colour. They average around 8 feet (2.5 meters) in length. Fast and deadly, these blue-tinged snakes are thought to be responsible for up to 20,000 deaths a year, though precise numbers are hard to come by. Africa's deadliest snake, the black mamba (Dendroaspis polylepis) can kill a person with just two drops of venom. Their venom belongs to the class of three-finger toxins, meaning they kill by preventing nerve cells from working properly. The snakes are born with two to three drops of venom in each fang, so they are lethal biters right from the get-go. By adulthood, they can store up to 20 drops in each of their fangs. 

Without treatment, a bite from this African snake is just about always lethal. In the case of the black mamba, the venom prevents transmission at the junction between nerve cells and muscle cells, causing paralysis. The toxin may also have a direct effect on heart cells, causing cardiac arrest. This was the case for a South African man who got bitten by a black mamba on his index finger, Ryan Blumenthal, of the University of Pretoria, reported. By the time he got to the hospital, within 20 minutes, he was already in cardiac arrest. Even though doctors treated him with antivenom, the man ended up dying days later, Blumenthal said. Blumenthal estimates it is responsible for the largest number of snake-related deaths in southern Africa. 

Black mambas are fast. They can move at around 12 mph (19 km/h). Black mambas live in large swaths of sub-Saharan Africa, in the following countries: Burkina Faso, Cameroon, Central African Republic, Democratic Republic of the Congo, South Sudan, Ethiopia, Eritrea, Somalia, Kenya, Uganda, Tanzania, Burundi, Rwanda, Mozambique, Eswatini, Malawi, Zambia, Zimbabwe, Botswana, South Africa, Namibia and Angola. They live in savannas, open woodlands and rocky hills. They like to sleep in hollow trees, abandoned termite mounds and in the cracks between rocks.

Russel’s viper (Daboia russelii)

Next on our list is a snake you really wouldn’t want to meet. The Russel’s viper is known to have one of the most excruciatingly painful bites of all. It is also known to be aggressive and quick to bite. Along with the Indian cobra, the common krait and the saw-scaled viper, it belongs to what are called “the Big Four”. These four snakes are responsible for causing the most medically significant snake bites. The Russel’s viper is the source of most of these, accounting for 43% of all snakebites. Thankfully an antivenom has been developed which can be used as treatment against bites from all the Big Four, saving many lives.

Russell's vipers are considered among the deadliest of the true vipers. It's hard to get accurate estimates, as many people who are bitten by snakes live in regions with poor medical care and never report their encounters with the deadly reptiles. But around 58,000 deaths are attributed to snake bites every year, and the Russell's viper (Daboia russelii) is responsible for the majority of these mortalities, according to research published in the journal PLOS Neglected Tropical Diseases. This species is considered one of the most deadly of the true vipers, researchers reported. In Sri Lanka, where this nocturnal viper likes to rest in paddy fields, they cause high mortality among paddy farmers during harvest time. The snake's venom can lead to an awful smorgasbord of symptoms: acute kidney failure, severe bleeding and multi-organ damage. Some components of the venom related to coagulation can also lead to acute strokes, and in rare cases, symptoms similar to Sheehan's syndrome in which the pituitary gland stops producing certain hormones. Victims typically die from renal failure. 

Common krait (Bungarus caeruleus)

This Big Four member is again excessively toxic, with an untreated mortality rate of around 80%. Unlike the Russel’s viper, however, the bite is often not painful, leading to false reassurance in victims. Its venom consists of strong neurotoxins which lead to muscle paralysis, respiratory failure and death. Thankfully however it is a nocturnal hunter, feeding on other snakes, small mammals and frogs at night. This means that you have to be quite unlucky to encounter one and are only likely to be bitten if you step on one in the dark. 

Indian cobra (Naja naja)

Perhaps the most iconic of all deadly snakes is the Indian cobra. It holds a special place in Hindu culture and folklore and is the species you might see with a snake charmer. As a member of the Big Four it is highly venomous and deadly, and unfortunately encounters with humans are frequent, as it tends to hunt rodents in populated areas. Although a bite from an adult cobra can kill, curiously there has been in the past a risky practice of using the venom of young individuals as a form of substance abuse. It apparently has psychoactive effects.

Puff adder (Bitis arietans)

Moving away from the Indian subcontinent, we come to the large and frightening puff adder. This species of viper is responsible for more fatalities than any other African snake. When threatened it is more likely to stay put than to flee, making it especially dangerous, and unfortunately, it has a habit of basking on footpaths. Before it strikes it will give a chilling warning, inflating its body and hissing loudly. Although the untreated mortality rate is fairly low (around 15%), serious bites can cause spreading necrosis and gangrene, which can lead to losing digits or limbs.

Common death adder (Acanthophis antarcticus)

The aptly named death adder is native to Australia, found in forest, woodlands and grasslands. Although not known to be aggressive, its dependence on camouflage and ambush for hunting its prey, including covering itself in leaves, means it is especially dangerous for humans venturing into bush who may step on one unawares. Its venom is also very potent, with an untreated mortality rate of about 60%. Although it is still widespread it is under threat from invasive cane toads. These introduced toads eat young death adders and adult snakes who eat them in return are poisoned by toxic glands on their skin. Although we don’t have cane toads in the UK, we do have our own damaging invasive species.

Common death adders are found across coastal areas of southern, eastern and northern Australia. They are recognizable thanks to their broad, triangular heads, short, thick bodies and thin tails. Common death adders are ambush predators and wait for prey, including frogs, lizards and birds, under leaves until they are ready to strike. Bites to humans are rare and normally involve a person stepping on one by accident. Their venom causes paralysis and can lead to death: Before the introduction of antivenom in the 1950s, about 60% of bites were fatal, according to the Australian Museum. The most recently recorded human fatality from a common death adder bite was in 1930. 

King cobra (Ophiophagus hannah)

The next on our list holds the distinction of being the world’s longest venomous snake, at an impressive four metres on average, with a maximum record of 5.85 metres. Like the Indian cobra, the regally named king cobra holds a special cultural significance in the Indian subcontinent. It is unfortunately threatened by both habitat destruction and poaching for use in traditional Chinese medicine. Killing a king cobra is a serious offence in India with imprisonment of up to six years. King cobras are the longest venomous snakes in the world.  The king cobra (Ophiophagus hannah) is the world's longest venomous snake, measuring up to 18 feet (5.4 m). The snake's impressive eyesight allows it to spot a moving person from nearly 330 feet (100 m) away. When threatened, a king cobra will use special ribs and muscles in its neck to flare out its "hood" or the skin around its head; these snakes can also lift their heads off the ground about a third of their body length. Its claim to fame is not so much the potency of its venom, but rather the amount injected into victims: Each bite delivers about 7 milliliters (about 0.24 fluid ounces) of venom, and the snake tends to attack with three or four bites in quick succession. Even a single bite can kill a human in 15 minutes and an adult elephant in just a few hours.

Eastern Diamondback Rattlesnake (Crotalus adamanteus)

The first American snake on our list, as well as the first rattlesnake, this is in fact the deadliest snake in North America. Compared to Asia this is fairly small fry however, as only about 5 people per year die from snakebites in the US. The Eastern Diamondback Rattlesnake is a particularly large and heavy snake, weighing as much as 15.4kg, with frightening 1-inch long fangs. It carries a powerful hemotoxin in its venom, which damages red blood cells and causes tissue damage. The untreated mortality rate of its bite is around 20%. The eastern diamondback rattlesnake is the biggest venomous snake and is found across southeastern states of USA. Eastern diamondback rattlesnakes (Crotalus adamanteus) is also the largest rattlesnakes and are found across southeastern states including Florida, North Carolina, South Carolina, Alabama, Georgia, Mississippi and Louisiana. They are ambush predators and tend to lie quietly coiled away waiting for prey to approach. They can strike a victim up to two-thirds of their body length away, injecting a large quantity of venom with each bite. The species is not aggressive to humans, and bites tend to occur if a snake is intentionally harassed or accidentally stepped on. Their venom, which the snakes administer in about 75% to 80% of bites, kills red blood cells and causes severe tissue damage. If left untreated, the fatality rate for an eastern diamondback bite is between 10% and 20%.  

Eastern brown snakes

Eastern brown snakes are Australia's deadliest snake species.  Eastern brown snakes are endemic to eastern Australia and are responsible for more human fatalities than any other snake species in the country. Their venom is highly potent, containing powerful toxins which can cause paralysis and internal bleeding. The initial bite is often painless. "They're the only snakes in the world that regularly kill people in under 15 minutes," Bryan Fry, who studies venom at the University of Queensland, said. "Even more insidiously than that is that for the first 13 minutes, you're going to feel fine." They generally hunt during the day and are often found in the suburbs of cities and large towns, putting them in close contact with humans. Many eastern brown snake bites are the result of people trying to kill them. 

Fer-de-lance

Fer-de-lances are pit vipers from Central and South America. A bite from a fer-de-lance (Bothrops asper) can turn a person's body tissue black as it begins to die. These pit vipers, which live in Central and South America and are between 3.9 and 8.2 feet (1.2 and 2.5 m) long and weigh up to 13 pounds (6 kg), are responsible for about half of all snakebite venom poisonings in Central America. Viper venom belongs to a class of proteins called metalloproteases. These can digest tissue, causing tissue to die (necrosis), swell (edema) or bleed. Fer-de-lance venom is also an anticoagulant (a substance that hinders blood clotting), a bite from this snake can cause a person to hemorrhage. 

Boomslang

Boomslang snake venom causes victims to bleed internally.  About 24 hours after being bitten on the thumb by a juvenile boomslang (also called a South African green tree snake), herpetologist Karl Patterson Schmidt died from internal bleeding from his eyes, lungs, kidneys, heart and brain. The snake had been sent to Schmidt at The Field Museum in Chicago for identification. Like others in the field at the time (1890), Schmidt believed that rear-fanged snakes like the boomslang (Dispholidus typus) couldn't produce a venom dose big enough to be fatal to humans. The boomslang, which can be found throughout Africa but lives primarily in Swaziland, Botswana, Namibia, Mozambique and Zimbabwe, is one of the most venomous of the so-called rear-fanged snakes. Such snakes can fold their fangs back into their mouths when not in use. As in other deadly snakes, this one has hemotoxic venom which causes their victims to bleed out internally and externally. 

With an egg-shaped head, oversized eyes and a bright-green patterned body, the boomslang is quite the looker. When threatened, the snake will inflate its neck to twice its size and expose a brightly coloured flap of skin between its scales. Death from a boomslang bite can be gruesome. As Scientific American describes it: "Victims suffer extensive muscle and brain hemorrhaging, and on top of that, blood will start seeping out of every possible exit, including the gums and nostrils, and even the tiniest of cuts. Blood will also start passing through the body via the victim's stools, urine, saliva and vomit until they die." Luckily, there is antivenom for the boomslang if a victim can get it in time.

Eastern tiger snake

Eastern tiger snakes kill an average of one human a year. Native to the mountains and grasslands of southeast Australia, the eastern tiger snake (Notechis scutatus) is named for the yellow and black bands on its body, though not all populations sport that pattern. Its potent venom can cause poisoning in humans in just 15 minutes after a bite and is responsible for at least one death a year on average. 

Banded krait

Banded krait venom stop victims' lungs from working effectively. The banded krait (Bungarus fasciatus) is a slow mover during the day and is much more likely to bite after dark. The snake's venom can paralyze muscles and prevent the diaphragm from moving. This stops air from entering the lungs, effectively resulting in suffocation. 

Coastal taipan

Coastal taipans are incredibly fast and can jump into the air fangs-first to attack. You could be bitten multiple times before becoming aware of the coastal taipan (Oxyuranus scutellatus), because of its incredible speed. When threatened, this snake, which lives in the wet forests of temperate and tropical coastal regions, will lift its whole body off the ground as it jumps fangs-first with extraordinary precision and injects venom into its enemy. Before 1956, when an effective antivenom was produced, this snake's bite was nearly always fatal. The snake's venom contains neurotoxins, which prevent nerve transmission.