Every year somewhere between 20,000 and 125,000 people die from snake bites. This makes them by far the most dangerous group of vertebrates on Earth.
Like all lists on Planet Deadly there is some balancing here of what criteria actually define the world’s deadliest snakes. Other lists on various websites should probably be more accurately titled as the “World’s most venomous snakes” and this was partially covered in our article on the most venomous animals.
1. Black Mamba
The feared Black Mamba is found throughout many parts of the African continent. They are known to be highly aggressive, and strike with deadly precision. They are also the fastest land snake in the world, capable of reaching speeds of up to 20km/h. These fearsome snakes can strike up to 12 times in a row. A single bite is capable of killing anywhere from 10-25 adults. The venom is a fast acting neurotoxin. Its bite delivers about 100–120 mg of venom, on average; however, it can deliver up to 400 mg. If the venom reaches a vein, 0.25 mg/kg is sufficient to kill a human in 50% of cases. The initial symptom of the bite is local pain in the bite area, although not as severe as snakes with hemotoxins. The victim then experiences a tingling sensation in the mouth and extremities, double vision, tunnel vision, severe confusion, fever, excessive salivation (including foaming of the mouth and nose) and pronounced ataxia (lack of muscle control). If the victim does not receive medical attention, symptoms rapidly progress to severe abdominal pain, nausea and vomiting, pallor, shock, nephrotoxicity, cardio toxicity and paralysis. Eventually, the victim experiences convulsions, respiratory arrest, coma and then death. Without antivenin, the mortality rate is nearly 100%, among the highest of all venomous snakes. Depending on the nature of the bite, death can result at any time between 15 minutes and 3 hours.
2. Common Lancehead
The lanceheads are a family of pit-vipers (Bothrops) found throughout Central and South America. Together they are responsible for the vast majority of snakebite deaths in the region. Often living in populated areas these snakes are fast and described as excitable and unpredictable when encountered.
Worthy of particular mention amongst this group are the common lancehead (B. atrox), the terciopelo (B. asper) and the jararaca (B. jararaca). All are large snakes measuring around the 2 metre (6.5ft) mark and have powerful hemotoxic venom.
Unlike the previous two snakes which possess a neurotoxic venom, the lancehead’s venom is hemotoxic. Obviously, no one in their right mind wants to be bitten by any of the snakes on this list, but given the choice I’d go for a snake with neurotoxic venom any time. Hematoxins work by destroying blood cells and breaking down the body’s tissues and organs. As you might imagine this is both extremely painful and can result in irreversible damage. Bites from such snakes frequently result in the need to amputate limbs, even after prompt treatment.
The bite from a lancehead will cause local swelling and pain often followed by blistering and bruising. Systemic symptoms usually involve hemorrhaging internally and from the gums, eyes etc. Whilst this may lead to fatal shock, death may also result from kidney failure.
3. Death Adder
You know that famous legend about Cleopatra using a snake to kill herself? The type of snake she supposedly used was a death adder. You can find these snakes throughout Australia, New Guinea, and other regions. A bite can result in paralysis, respiratory arrest, and death inside of only six hours. With fast treatment, a patient is unlikely to die, but without treatment, about 50% of bites are lethal. Death adders also prey on other snakes.
4. Inland Taipan
While it’s difficult to be as impressed by the Inland Taipan after learning about the concentration of venom in a Belcher’s Sea Snake bite, it’d be foolish to discount the Taipan just because its bite can only kill as many as 100 people! Taipans usually avoid human contact, however, and you are unlikely to ever encounter one.
5. Blue Krait
This snake is not as well known as some, but its venom is 16 times more potent than that of the cobra! There also is no really good antivenin to use, which makes it quite deadly. The Blue Krait tends to keep to itself and usually only comes out at night, though, so it is generally easy to avoid.
6. Philippine Cobra
This snake is easily spotted because of its wide neck collar. While cobras inspire fear, most types of cobras don’t even make this list. The Philippine Cobra, however, does. It doesn’t even have to bite you to poison you. All it has to do is spit, and it can do that from 3 meters away and still hit you. Paralysis from the venom can cause death within thirty minutes.
7. The King Cobra
The king cobra (Ophiophagus hannah) is the longest venomous snake in the world. Its bite delivers a tremendous amount of paralysis-inducing neurotoxins. The snake’s venom is so strong and so voluminous that it can kill an elephant in just a few hours. Death also results in at least 50 to 60 percent of untreated human cases.
8. Saw Scaled Viper
This viper is usually found in the Far East and Middle East, and generally comes out after dark. The main danger with this creature is that the venom is so slow-acting that a victim may make the mistake of waiting too long to seek treatment. Treatment can prevent death in the majority of cases, but without it, death will result slowly and painfully over the course of two to four weeks.
Now you know the most dangerous snakes in the world. Some are easy to avoid, like the Blue Krait, while others, like the Eastern Brown Snake, may sneak up on you even in the middle of a busy city. Some snakes are dangerous because of the speed or ferocity of their attacks, others because of how common and widespread they are, and still others because their toxins are so deadly. As you can see, though, the majority are not aggressive, and will steer clear of you if you steer clear of them. And even if you do get bit, with prompt treatment, in most cases you will live.