What Are “The Big Four” Snakes, and Why Are They So Deadly?

The Big Four Snakes
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Written by Kirstin Harrington

Updated: June 1, 2023

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While many people have a great fear of snakes, others love these scaly critters. The individuals who call India home share it with nearly 300 species of snakes! Rest assured only 60 of these species are venomous. 

Every year, the residents of India fall victim to venomous snake bites, and thousands of these bites are fatal.

The “Big Four” are the main species of snakes which are responsible for the most snakes bites (out of the nation’s 60 venomous snake species),

They include: Russell’s viper (Daboia russelii), the common krait, (Bungarus caeruleus), the spectacled cobra, (Naja naja), and the saw-scaled viper, (Echis carinatus).

Types of Snake Bites

There are two main types of snake bites: dry and venomous. Dry bites are snake bites that do not release any venom. You’ll typically find this type of bite with non-venomous snakes, as one might imagine. A bite from a venomous snake is far more hazardous. 

When venomous snakes bite, they willingly release venom. They have control over how much venom they release, and envenoming or poisoning occurs in 50 to 70% of venomous snake bites

Even if the bite isn’t severe, every snakebite should be addressed as a medical emergency unless you’re certain it was caused by a non-venomous snake. Any delay in seeking medical attention after being bitten by a poisonous snake can result in significant damage or, in the worst situation, death.

Identifying The Big Four 

As the name suggests, The Big Four are the most dangerous and prevalent snakes that can be found just about anywhere in India, including houses! Let’s take a look at each one and go over identifying features to keep you as safe as possible! 

1. Russell’s Viper

Deadliest Snakes - Russell's Viper
Rusell’s vipers have a mortality rate of around 2.6% in India.

©jaroslava V/Shutterstock.com

These snakes are swift and deadly, capable of striking victims from up to five feet away. This species of viper is responsible for tens of thousands of deaths in India each year. The scales on their strong bodies are deeply keeled. The color is often yellowish-brown, with three rows of a distinctive chain arrangement. 

There are also black bands on its body, letting the snake stand out even more. Like many other snakes, their triangular heads resemble a V and have vertical pupils. It’s not uncommon for this type of snake to have several regional names all across India. 

It gets its name after herpetologist Patrick Russell discovered that the snake was highly venomous. He experimented on dogs and chickens and quickly saw how dangerous these snakes are. 

You can find Russell’s Vipers all around the country, yet they seem to steer clear of the northeastern area. This species of snake loves a dry environment and you won’t find them in wet or dense rainforests. 

They naturally seek shelter in thick bushes, leaves, farmlands, and scrub jungles. When the steaming temperatures of India are too much for this serpent, they burrow into termite mounds and rodent burrows, surely to find a snack in their hideaway. 

Russell’s Viper prefers to do all of their hunting during nighttime hours. They’ll hunt just about anything they can find, including other Russell’s Vipers! Their preferred meal consists of rodents and lizards

This snake is known to be highly intelligent, and just a drop of their venom is enough to render an unfortunate critter dead. Unlike other deadly snakes, Russell’s Viper doesn’t have to hold onto its prey as it injects venom. A single jab is all it takes to take the other animal down.  

Having an unexpected bite from one of these critters is far from pleasant. There is a unique mixture of toxins in their venom. Symptoms occur almost immediately after a bite. Some of the most common symptoms include:

  • Renal failure
  • Shock
  • Spontaneous Hemorrhage
  • Intravascular coagulation 
  • Kidney failure 

2. Common Krait

Deadliest Snakes - Common Krait
Common krait bites can have up to an 80% fatality rate if not treated.

©Arabindu Sardar/Shutterstock.com

The Bungarus caeruleus, also known as the Common Krait, is a nocturnal serpent that slithers through the shadows of the moonlight in hopes of finding prey. They like to steer clear of light and busy areas and you can find them in the grasslands, forests, rocky terrain, and inside the homes of people living in peninsular India. 

The Blue Krait has quite the reputation as well. This species is known for having the most potent venom! Thankfully, it’s easy for the public to identify these snakes. They have long, cylindrical bodies that are between three and four feet long. 

Their scales are usually glossy jet black or blue-black. You’ll find twin white bands all around their body, except for the neck region. Common Kraits have white underbelly areas, small black eyes, and tongues that are shockingly wide-forked. 

This species of snake loves to spend time in small spaces such as brick piles and wall crevices. It’s not uncommon for people in India to sleep on the floor, opening themselves up to these sneaky creatures. Common Kraits only tend to bite humans as an act of self-defense. Their predatory bites seem to be much worse than their defensive ones, so steer clear if you happen to cross paths with one of these snakes. 

Snakes, insects, rodents, and lizards are the main diet for Kraits. These animals don’t stand a chance against the most potent venom in India. As soon as this snake bites, it will shut down the nervous system of the victim. 

3. Spectacled Cobra

Deadliest Animal in the World: Snakes
Spectacled cobra, Naja naja, Bangalore, Karnataka. The Indian cobra is one of the big four venomous species that inflict the most snakebites on humans in India.


A snake with many names, The Spectacled Cobra, also goes by Asian Cobra, Binocellate Cobra, and Indian Cobra. Many confuse this snake with the King Cobra due to their similar geographical location. As the third of the big four, the Asian Cobra is responsible for a majority of the venomous bites throughout India. 

You’ll find these slithering serpents everywhere except for deserts and high-altitude areas of the country. Indian cobras in northern India tend to be dark brown, while others in northwestern India are black and southern ones are yellowish-brown. 

This snake has a distinct round hood with many shiny scales and surrounds the snake’s head. 

This species tends to be a bit huskier than other snakes and they grow between three and five feet long. Unlike other venomous snakes in the big four, Indian cobras are active during the day, even though they also hunt at night. 

They tend to take shelter in small dens, the hollows of trees, and within termite mounds. This type of cobra eats lizards, rodents, frogs, and birds. One reason why this snake is so deadly is that once it has its eyes on its prey, it will remain extremely focused. 

Cobras hiss aggressively as well, which is normally seen as a threat. The venom of the Indian cobra is highly toxic, containing neurotoxin, which damages nerve tissue, and cardiotoxin, which damages the heart. Within 30 minutes and two hours after the attack, complications like as respiratory distress or cardiac arrest might occur. 

4. Saw-Scaled Viper

10 Most Venomous Animals - The Roman's Saw scaled Viper is the most dangerous snake in Africa and Asia
The Roman’s Saw scaled Viper is the most dangerous snake in Africa and Asia


©Luis Montero de Espinosa/Shutterstock.com

The Saw Scaled viper, or Echis carinatus, is the smallest of the four and is liable for the most medically significant snakebites and deaths in India. In India, there are five separate sub-species of these intriguing vipers, each with its own set of characteristics. The ones found in the Western Ghats of southern India, for instance, are quite little, coming in at around 15 inches at the longest.

However, those located in Rajasthan’s desert habitat can grow to be near twice as large. Saw Scaled vipers may be found all across India, however, they are more usually found in peninsular India and northwest India. Expansive bushy regions, rocky rough terrain, and rainforests are their preferred habitats.

The Saw Scaled vipers’ bodies are smooth all over. This indicates that each of the upward-oriented scales has a higher hump in the center. As a result, some snakes appear rough rather than smooth. Their short, thick bodies come in a range of patterns and colors, with the majority of white dots visible on their grey, brick red, light brown, or green bodies.

Their heads are trapezoidal, and their necks are wider, with straight pupils. They can be both hostile and unobtrusive in character. When challenged, these snakes clump their bodies together in the shape of an S in an attempt to flee the hazard. Because of the brushing of the scales together, this action can produce a harsh and scratchy, raspy sound. 

If you hear this, it’s probably a good idea to get as far away from the slithering critter as quickly as possible. Their tiny bodies enable them in moving in sidewinding movement on the ground with low surface tension. These vipers are reported to eat small animals, birds, lizards, and sometimes other snakes. They normally come out after dusk to forage for food.

How to Treat Snake Bites From The Big Four 

First and foremost, get medical help right away. This includes dialing 911 or contacting emergency services as quickly as possible since even if the bite isn’t particularly painful at first, you should still treat it as though it’s potentially life-threatening. 

The treatments can be facilitated by correctly identifying the snake, albeit this is quite difficult to do, which is why we went into great detail about the descriptions. 

  • If you have any jewelry or watches on, take them off since they might cut into your skin if swelling happens. 
  • Stay calm and still. Turn onto your side and relax in the recovery posture if possible. The venom will travel quicker through the body if you move about a lot. 
  • Apply a clean, dry bandage to the bite. If possible, employ a pressure immobilization bandage. This wrap should be applied securely around the bite. After that, tie another bandage over the whole limb to immobilize it.

While all of these precautions are beneficial, antivenom is the most effective therapy for a snake bite. Try to get antivenom to the bite victim as soon as feasible. Recognizing the snake’s size, color, and shape can assist your doctor in determining the best antivenom for the situation.

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About the Author

Kirstin is a writer at A-Z Animals primarily covering animals, news topics, fun places, and helpful tips. Kirstin has been writing on a variety of topics for over five years. She has her real estate license, along with an associates degree in another field. A resident of Minnesota, Kirstin treats her two cats (Spook and Finlay) like the children they are. She never misses an opportunity to explore a thrift store with a coffee in hand, especially if it’s a cold autumn day!

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