Snakes are some of the most feared animals on the planet. In fact, Ophidiophobia, or fear of snakes, is the second most common phobia worldwide. Around 1 in every 3 human adults is considered to have a fear of snakes to some degree, and in some rare cases, such phobia can be severe enough to trigger heart attacks and even lead to death.
While fear of snakes is understandable, such statistics tend to induce some questions, are snakes really that dangerous? And if so, what are the most dangerous species of snakes alive today?
According to the WHO, around 5.4 million people are bitten by snakes each year around the world. Of these, around 81,000 to 138,000 people die annually, with around three times as many permanent disabilities or amputations. Most of these numbers, however, are caused by a very small population of these reptiles, namely venomous snakes.
What are Venomous Snakes?
As the name suggests, these reptiles are a smaller part of the main snake group capable of producing venom. Snakes use their venom mainly as a defence mechanism to target or paralyze their prey. The venom is produced in their salivary glands and is injected using sharp pointed teeth known as fangs.
Are All Snakes Venomous?
No, not every snake is dangerous. There are around 3,900 species of snakes in the wild today. Out of these, only 725 are venomous, and even in these 700-something species, only around 250 can cause death in humans with a single bite.
That is, of course, not to say that non-venomous snakes are not dangerous; some species of such snakes can kill humans too. However, this is extremely rare, with only around 1 or 2 deaths worldwide per year. Even then, these deaths are usually from constrictor snakes that have been kept as pets, like pythons.
Even venomous snakes don’t inject venom with every bite. Research shows half of all venomous snake bites are dry, or in other words, without any venom. Venom is a valuable resource to these reptiles and is only used when necessary.
Most venomous snakes belong to one of three groups, namely:
Viperidae:
Vipers are perhaps the most well-known family of snakes. The Viperidae family consists solely of venomous snakes and has well-known members such as Copperheads, Rattlesnakes and Moccasins. Vipers have larger fangs than other venomous snakes (with Gaboon vipers’ fangs reaching up to around 2 inches), which can fold against the roof of their mouth when not in use.
Elapidae:
Elapids are known for their short fangs fixed on the upper front of the jaw. This family also has its fair share of well-known members, such as mambas, cobras, sea snakes and coral snakes.
Colubridae:
Colubrids are the largest family of snakes, with around 2,000 species, and makeup over half of the world’s snakes. The family contains a mix of venomous and non-venomous snakes. Colubrid fangs aren’t as developed as the vipers or elapids; thus, they have to “chew” on their targets to inject their venom. Due to this, most venomous species of colubrids aren’t considered dangerous to humans. The colubrid family members include Twig snakes, Keel snakes, Ratsnakes, Boomslang and many more.
How is the Potency of Snake Venom Determined?
Snake venoms are perhaps some of the most complex compounds around the world. Each venom is unique and has evolved differently throughout the years depending on the snake species.
The evolution of venom to cause a range of intense reactions is also influenced by the different types of prey each species likes to hunt. Depending on the snake, the venom can cause paralysis, haemorrhaging, inflammation and tissue death to capture different types of prey or attack specific parts of the human body.
The potency of snake venom is determined by experts using what is known as an LD50 test. The lethal dose 50, or LD50 for short, is a toxicology test that can be used to determine how dangerous a particular species of snake is, and it is exactly what the ranking on this list has been based on.
What Does the LD50 Test Mean?
The LD50 test stands for the quantity of material (given all at once), which causes 50% of the subjected test animals to die. While toxicologists can use many animals, LD50 tests are usually run on mice or rats.
To put it into simpler terms, the LD50 rating of a venomous snake is the amount of venom it took to kill 50% of the mice group it was administered to. A lower LD50 rating means it took a lower quantity of venom to kill 50% of the target group; thus, the lower the LD50 rating, the more toxic the venom.
Venomous snakes are responsible for many snake deaths and are usually more common in rural areas where the anti-venom isn’t readily available. However, the probability of being injected with venom also varies, as each snake has a different temperament and may inject a different amount of venom compared to other snakes from the same family.
Despite the variables, the LD50 ratings are a reliable source to determine the top 10 most venomous snakes in the world.
The 10 Most Venomous Snakes in the World
10. Black Mamba
Scientific Name: Dendroaspis polylepis
Length: 2 to 3 m (6.56 to 9.84 ft)
Weight: 1.6 kg (3.53 lbs)
Top Speed: 16 km/h (9.94 mi/h)
Lifespan: 11 years
Locations: Sub-saharan Africa
Conservation status: Species of Least Concern
The black mamba, also sometimes referred to as the black-mouthed mamba, commonly prefers relatively dry areas, such as rocky outcrops or semi-arid savanna, but you can also find it in moist savanna. Sometimes, they even pay visits to agricultural areas.
You can generally find them sheltering in rock crevices, termite mounds, tree cracks, and abandoned burrows. They enjoy basking twice, in the morning and afternoon, typically at the same location. They don’t appreciate the proximity of fewer than 40 meters or 130 feet with humans and may engage.
However, the engagements with black mambas are exaggerated as they only try to threaten away the approachers by exposing their black mouth, the reason behind their name, and flicking their tongue. The situation may escalate into a series of rapid attacks, causing serious envenomation, if the intruder doesn’t back away and further provokes its wrath.
Among all African snakes, the black mamba is the most feared because of the severity of its venom’s toxicity and the speedy onset of symptoms. The first symptom is a tingling sensation on the bite location, which turns into a metallic taste, drooping eyelids, and gradual onset of bulbar palsy in the next 10 minutes.
A human may collapse within 45 minutes of a black mamba’s bite and may end up dead, if not provided appropriate antivenom treatment, in the next 7 to 15 hours, due to respiratory failure, causing cardiovascular collapse.
A black mamba typically delivers 100 to 120 mg of venom on average with a single bite. The highest recorded dosage stands at 400 mg.
9. Fer-de-lance
Scientific Name: Bothrops asper
Length: 1.2 to 1.8 m
Weight: Up to 6 kg (13.23 lbs)
Lifespan: 15 to 21 years
Locations: Northeast Mexico, Central America, Columbian and Ecuadorian Andes, Venezuela, and Trinidad
Conservation status: Species of Least Concern
The fer-de-lance, also referred to as terciopelo, the Spanish word for ‘velvet’, is one of the largest pit vipers in the world. It has a light to dark brown body with yellow zig-zag lines on each side. It is the most feared snake in Central and South America because of being the main culprit of fatal snakebite incidents within its territory.
The female fer-de-lance is bulkier than a male, with a larger head and bigger fangs (around 2.5 cm or 1″). These snakes are typically found in tropical rainforests and evergreen forests, but you can also spot them in drier areas of tropical deciduous forests, thorn forests, and pine savannah near freshwater bodies.
These snakes bask in the sun during the day and camouflage themselves in leaf litter or under forest cover at night to prey on rats and mice. They are capable of inflicting some serious damage if provoked but usually prefer to flee when threatened.
However, this doesn’t mean that you should be careless and play with them as they can be very excitable and unpredictable, and go for the S-coiled defence when feeling attacked. This is one of the reasons why, the fer-de-lance, alongside the South-American rattlesnake, causes the most snakebites in Yucatán, Mexico.
The fer-de-lance can also bite above the knee because of its capability to raise the head high. They also throw fine jets of venom over a distance of at least 1.8 m (6 ft).
The most immediate symptoms of a fer-de-lance bite include pain at the bite location, fluids from the puncture marks, and swelling that keeps on increasing for the next 36 hours. These are accompanied by multiple systemic thromboses, local necrosis, and gangrene in case of severe envenomation within the next 48 hours; treatment may require amputation. The time of death in the case of a fer-de-lance depends on the amount of venom injected, but symptoms onset may take 15 minutes.
A fer-de-lance bite carries as much as 1530 milligrams of venom.
8. Boomslang
Scientific Name: Dispholidus Typus
Length: 1 to 1.6 m (3.28 to 5.25 ft)
Weight: 0.175 to 0.51 kg (0.38 to 1.12 lbs)
Lifespan: 8 years
Locations: Botswana, Mozambique, Namibia, and South Africa
Conservation status: Species of Least Concern
The boomslang is hands down the most dangerous snake of the Colubridae family. It is one of the top snakes in the rear-fanged category and is also known as the South African Green Tree Snake.
Boomslang snakes have a very potent venom that can easily take human lives with a very small amount. However, due to their rear fangs, they find it very hard to inject venom in one go and instead have to “chew” on their target.
Although a single bite of the snake can easily take the life of a fully grown human adult, it is not the venom that causes the boomslang snake to be feared. Rather it is the false sensation of safety.
Victims of the boomslang snake can easily mistake its bite for a dry attack (no venom injected). However, that is only until the side effects start showing; by then, it is already too late.
The snake typically eats lizards and birds and is tree-dwelling. They are very alert in nature and prefer to avoid confrontation when possible. Instead, when feeling threatened, they tend to inflate their throats in an attempt to make themselves look bigger.
The initial symptoms of the bite may not kick in until several hours (up to 24) after the incident. This can lead to a false sense of security as the venom continues to spread throughout the system, causing internal bleeding in tissues and organs. As the side effects begin to kick in, the victim may experience blood in stool and urine. The venom also attacks the nervous system causing dizziness, neurological disturbances and difficulty breathing. Delayed treatment of the venom can lead to organ failure and even death in some cases.
A boomslang snake bite only carries 1-8 mg of venom at a time.
7. Eastern Tiger Snake
Conservation status: Species of Least Concern
Scientific Name: Notechis scutatus
Length: 1.2 to 1.6 m
Weight: 0.36 to 1.32 kg (0.8 to 2.9 lbs)
Lifespan: 5 to 15 years
Locations: Australia
The Eastern Tiger snake is one of the deadliest snakes in Australia. It’s characterized by the unique yellow and black stripes on its entire body (hence the name).
The venom of the tiger snake contains a very strong blood clotting and paralyzing agent, which can prove to be fatal to humans in as little as 10-20 minutes after the bite. These snakes are solitary and prefer to roam grasslands and mountains, mainly within Southeast Australia.
Tiger snakes prefer to avoid people when necessary. However, they can take a very aggressive approach when startled. It mainly feeds on small mammals and other reptiles, birds and fish. Tiger snakes love to hunt in densely popular areas and are responsible for at least one human death in Australia annually.
The bite from an eastern tiger snake can cause immediate swelling, bruising and redness around the area of the bite. Within the next few hours or a day, the victim experiences nausea, headaches, weakness, fever and abdominal pain. Severe envenomation can also cause paralysis, severe bleeding disorders, difficulty bleeding or swallowing, and even death if the anti-venom is not administered in time.
The venom yield from an eastern tiger snake can be anywhere between 35 to 65 mg at a time. It takes only 3 mg at a time to be lethal to an adult male!
6. Russell’s Viper
Conservation status: Species of least concern
Scientific Name: Daboia russelii
Length: 1.2 to 1.6 m
Weight: 7 to 10 kg (15 to 22 lbs)
Lifespan: 15 years
Locations: East Asia, Southeast Asia, South Asia
Russell’s Vipers, also known as Chain Vipers, are one of the deadliest snakes in Asia. These snakes are easy to identify due to the distinctive patterns on their body. It is considered the most dangerous snake in India, responsible for more snake bites and deaths than any other venomous snake in the area.
Russell’s snakes are known to hiss very loudly when threatened and do not hesitate to attack. They release large amounts of venom at once and may even hold on to their target for several seconds after biting.
These snakes feed primarily on rodents but also occasionally hunt other reptiles, scorpions, and land crabs. They hunt primarily during the nighttime but can also be found during the day in cooler weather.
Victims of Russell’s snake usually report bruising, redness and pain in the area of the bite. This pain has been reported to continue for as long as four weeks after the bite and treatment! As the onset of symptoms continues, patients may experience dizziness, weakness and eventually significant coagulopathy and acute renal failure. Bites from certain subspecies may also induce dysarthrias, ptosis and generalized weakness. Their venom can also cause severe tissue damage, and even after treatment, around 29% of survivors suffer damage to their other organs and the Pituitary glands. If treated promptly, victims may succumb to the damage even after the bite has been treated or deal with its side effects for the rest of their lives.
Adult Russel’s snakes have reportedly released as much as 130 to 250 mg of venom at once.
5. Saw-scaled Viper
Conservation status: Species of least concern
Scientific Name: Echis carinatus
Length: 0.30 to 0.70 m
Weight: 0.82 to 2.40 (1.8 to 5.3 lbs)
Lifespan: 5-15 years
Locations: Africa, India, Middle East, Southeast Asia
Although the Saw scaled viper’s venom may not compare to the others on this list, it is still considered one of the most dangerous snakes in the world. Why? Simply because of their temperament.
These vipers are small, highly irritable and aggressive and cause the highest number of human deaths across the globe annually. They prefer hunting reptiles, arthropods, amphibians, and even smaller snakes.
These snakes prefer to bury themselves in the sand in a way that keeps only their head visible. With their mahogany, tan or brown colours, they blend right in, and it gets very easy to step on them and incur their wrath. When threatened, these vipers produce a raspy sound by rubbing their scales together.
A saw-scaled viper bite can cause swelling and discomfort within minutes, which can spread to the entire limb within 12-24 hours in rare cases. Patients get anuria or oliguria within a few hours, which may persist for up to 6 days after the bite. In more serious cases, bite victims may experience coagulation, haemorrhage defects, melena, hemoptysis, and hematemesis, which can induce hypovolemic shock and lead to organ failure or death.
The saw-scaled viper can inject up to 12 mg of venom, whereas the lethal dose for an adult is only around 5 mg!
4. Banded Krait
Conservation status: Species of least concern
Scientific Name: Echis carinatus
Length: 0.30 to 0.70 m
Weight: 0.82 to 2.40 (1.8 to 5.3 lbs)
Lifespan: 5-15 years
Locations: Africa, India, Middle East, Southeast Asia
Although the Saw scaled viper’s venom may not compare to the others on this list, it is still considered one of the most dangerous snakes in the world. Why? Simply because of their temperament.
These vipers are small, highly irritable and aggressive and cause the highest number of human deaths across the globe annually. They prefer hunting reptiles, arthropods, amphibians, and even smaller snakes.
These snakes prefer to bury themselves in the sand in a way that keeps only their head visible. With their mahogany, tan or brown colours, they blend right in, and it gets very easy to step on them and incur their wrath. When threatened, these vipers produce a raspy sound by rubbing their scales together.
A saw-scaled viper bite can cause swelling and discomfort within minutes, which can spread to the entire limb within 12-24 hours in rare cases. Patients get anuria or oliguria within a few hours, which may persist for up to 6 days after the bite. In more serious cases, bite victims may experience coagulation, haemorrhage defects, melena, hemoptysis, and hematemesis, which can induce hypovolemic shock and lead to organ failure or death.
The saw-scaled viper can inject up to 12 mg of venom, whereas the lethal dose for an adult is only around 5 mg!
3. King Cobra
Conservation status: Vulnerable (Due to poaching and loss of habitat)
Population: Unknown but Decreasing
Scientific Name: Ophiophagus Hannah
Length: 3.5 to 4 m (11 to 13 ft)
Weight: 6 to 9 kg (13 to 20 lbs)
Lifespan: 20 to 30 years
Locations: South Asia, Southeast Asia
King Cobras rank very high on the list of deadliest snakes. Although their venom isn’t as potent as the other listings, the sheer amount of venom they can inject in a single bite makes them very dangerous.
The average king cobra can inject enough venom to take down an adult elephant in a single bite! These snakes measure 3 to 4 m and flatten their necks into a hood and lift a part of their body off the ground when threatened.
Although they usually lift a third of their body in this state, some King Cobras are large enough to see eye to eye with a human being! Fortunately, these snakes prefer avoiding confrontation and residing deep in the forests.
King Cobras are also different from other snakes because they care for their offspring. They’re the only snakes that prefer to build an entire nest for their eggs and protect them until they hatch. These snakes usually eat other snakes (even venomous) but may also hunt rats and other rodents if the food supply is scarce.
An adult human male may succumb to King Cobra’s venom within 20-30 minutes, depending on the amount of venom injected. Initial symptoms include redness and swelling on the site of the bite, along with a rapid onset of systemic symptoms that may take anywhere between a few minutes to an hour. These include a drop in blood pressure, dizziness, respiratory failure and cardiac arrest.
An adult King cobra can inject between 400-600 mg of venom in a single bite, which is enough venom to kill 20 adult humans!
2. Coastal Taipan
Conservation status: Species of Least Concern
Scientific Name: Oxyuranus scutellatus
Length: 2 to 3 m
Weight: 1 to 2 kg (2.2 to 4.4 lbs)
Lifespan: 10 to 15 years
Locations: Northern and Eastern Australia
Although the coastal taipan isn’t as venomous as the Inland Taipan, it isn’t far behind in comparison. Coastal taipans are also known as common taipans and can strike frighteningly fast with very high accuracy.
Their venom had a 100% fatality rate before their anti-venom was discovered. Even now, in cases where the anti-venom has been registered within two hours of the bite, the venom of the common taipan can change the bodily functions of its victims for the rest of their lives.
Even after treatment, victims of coastal taipan are at a high risk of acute kidney failure and respiratory paralysis.
Bites of coastal taipans are very painful and cause swelling almost immediately. The symptoms of venom can set in rapidly and cause irregular heartbeats and a rapid drop in blood pressure. In cases of severe envenomation, respiratory distress can occur, which leads directly to respiratory failure and death by suffocation. Other cases of severe envenoming with delay in anti-venom administration can also result in neuromuscular paralysis.
The average coastal taipan can inject between 120 to 400 mg of venom in a single bite which is enough to kill 56 human adults at once!
1. Inland or Western Taipan
Conservation status: Species of least Concern
Scientific Name: Oxyuranus microlepidotus
Length: 1.8 to 2.5 m
Weight: 1 to 2 kg (2.2 to 4.4 lbs)
Lifespan: 10 to 15 years
Locations: Central and Eastern Australia
The inland taipan is considered to be the most venomous snake on the planet. Luckily, this snake prefers to live in remote areas in the flood plains of Australia and thus rarely ever has human encounters.
When threatened, the inland taipan curves its body into an S shape before releasing single or multiple attacks onto its target. The inland taipan’s venom can take effect in as little as an hour and is more than enough to dispatch a human adult easily.
These snakes usually set out during the day, particularly in the morning, to hunt for prey and bask in the sun. However, they can also be found in the afternoons, sometimes on cooler days. Inland taipans mainly eat rodents and generally prefer to be left alone. Although they’re also known as “fierce snakes“, that is more so because of the potency of their venom rather than their temperament, which remains to avoid conflict.
The Inland taipan is an extremely fast and accurate snake with venom that has evolved to target warm-blooded animals.
Bites of the inland taipan are relatively painless. The bite’s symptoms can take between a few minutes to 12-24 hours to appear, depending on the dose of venom administered, and can cause irregular heartbeats and a rapid drop in blood pressure. In cases of severe envenomation, respiratory distress can occur, directly leading to respiratory failure and death by suffocation. Other cases of severe envenomation include hemolytic, coagulopathic, and neurotoxic reactions, which could rapidly lead to paralysis or death. The Inland taipan can inject between 44 to 110 mg of venom in one bite. For reference, 100 mg of inland taipan venom is enough to easily kill 100 adult human males!
Venomous vs Poisonous Snakes
Although many people like to use the words “poisonous” and “venomous” interchangeably, they do not mean the same thing. Almost all snakes are venomous, not poisonous. So what exactly is the difference between the two, and are there actual poisonous snakes in the wild?
While both poison and venom are harmful toxins, the difference between the two is how they enter the body. Poisonous toxins can show their effect by ingestion or even a simple touch (think arsenic or poison ivy). On the other hand, venomous substances must be injected into the body, or at least break the skin, to have any effect.
In simpler terms, you’ll be safe for the most part if you accidentally touch venom by hand; poison, on the other hand, is actively absorbed by the skin and will begin to show its effects if touched barehanded. Hence, almost all snakes are venomous since their toxins would not have any effect if not injected directly into the body.
Of course, that does not mean actual “poisonous” snakes do not exist. Only two groups of snakes are known to be poisonous, these are:
North American Garter Snakes:
These snakes are not naturally poisonous themselves. These snakes can kill newts and survive; however, in doing so, they appear to become temporarily poisonous. Fun fact, a single newt secretes enough toxin to kill 12 adult humans from its skin! Garter snakes have evolved to successfully eat a newt and survive, only to become poisonous themselves.
Asia’s Keelback Snakes:
Like the North American Garter snakes, Asia’s Keelback snakes also get their toxins from their choice of prey, only this time, it happens to be toads. Furthermore, unlike the garter snakes, keelback snakes can keep the toxins in special glands found in their neck.
What to do if You Encounter A Venomous Snake?
Since you’re already familiar with venomous snakes, here are the do’s and don’ts if you ever happen to encounter or get bitten by one:
- Remember, snakes are more afraid of us than we are of them. Snakes generally prefer to leave when they hear humans approaching. Should you ever encounter a snake, it is usually because you caught them off guard, and the best course of action would be to leave them alone unless you are a trained snake wrangler.
- If bitten, remain calm and try to move as little as possible.
- DO NOT cut the wound or try to suck the venom out using your mouth.
- Remove any constricting items such as watches, jewellery or rings and do not apply heat or ice to the wound.
- Do not apply ointments or lotion to the area; seek medical help immediately. Try not to wash the wound, as residual venom might identify the snake you were bitten by.
- Apply a pressure bandage on the area of the bite and mark down with a pen its exact location on the bandage. After that, try to cease all movement and wait for medical assistance.
Conclusion
Even though a large majority of snakes are non-venomous and relatively harmless to humans, it’s better to be vary of every snake you cross. Non-venomous snake bites may be harmless, but the pain is still not something you’d like to experience for yourself.
Snake venom may have a lot of destructive properties, but it also has the potential to heal too when used wisely. The research into venom and its beneficial applications is a complicated topic with massive potential for the medical industry. The proteins in snake venom have been used to treat conditions such as heart attacks, strokes, Alzheimer’s and high blood pressure.
The potential of snake venom under the right conditions is very high; unfortunately, of the 100,000 annual deaths from snakebites, a large chunk is from under-developed countries that do not have instant access to anti-venom.
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FAQs
Which snake is the most venomous in the world?
The Inland Taipan is considered to be the most venomous snake in the world. It has the most toxic LD50 rating in mice and can cause blood clotting and paralysis of the target’s nervous system.
Which country has the most snakes?
Brazil has the highest number of snakes in the world. The country has around 375 species of snakes (both harmless and dangerous). Brazil has more than half of the South American rainforest, which provides the perfect breeding grounds for these snakes.
Which snake has killed the most people in the world?
The Saw-scaled viper kills the highest number of people annually. The snake is considered to cause more fatalities than all other snakes on this list put together. Although its venom isn’t as potent as some of the other snakes on this list, its highly aggressive nature and presence in densely populated rural areas with little to no access to anti-venom is what makes it especially deadly.
Where do snakes bite the most?
Most snake bites occur on the ankles, feet and hands!