The scariest of snakes are those with a deadly bite – those that inject a lethal venom which slowly leads to death if left untreated. Thankfully, only one of the eight most venomous snakes in the world is found in the U.S.
Read on to find out which of the about 600 venomous species on Earth (and a few in North America) you should look out for and where…
First, let’s talk just a bit about that deadly venom.
Venom’s potency is measured based on the median lethal dose in mice, but since there are many different types of venom, even this can be misleading. There are three distinct toxic venoms: cytotoxic, hemotoxic, and neurotoxic.
- Hemotoxic venom attacks the heart and cardiovascular system
- Neurotoxic venom damages the nervous system and brain.
- Cytotoxic venom is localized to the site of the bite, and is rarely as dangerous as other forms.
How Common are Snake Bites?
Take comfort: Over a 5-year period, less than 4% of the venomous bite injuries in U.S. emergency rooms were from snakes.
[Source: Trauma Surgery & Acute Care Open, the American Association for the Surgery of Trauma’s open access journal]
Another major factor in determining dangerous snakes is the likelihood of human encounter. Honestly, this is where the big difference between “most venomous snakes” and “deadliest snakes” comes into play.
Many of the world’s most venomous creatures rarely make contact with humans, so they, technically, aren’t that dangerous.
We’ve cross-referenced countless rankings of the world’s most dangerous and most venomous snakes. From there, we took the ones that appear most frequently and have created a quick-reference guide below. (We cannot be held accountable for snake-induced nightmares.)
1. Inland Taipan
Binomial Name: Oxyuranus microlepidotus
AKA: Western taipan, fierce snake, small-scaled snake
Venom Detail: Considered by far the most toxic of any snake, mycotoxins cause muscles to dissolve, while neurotoxins cause paralysis. One bite is lethal enough to kill 100 fully grown men, and it can do so in as little as 30 minutes.
Habitat: Acclimated to hot and dry weather, inland taipans live in semi-arid regions of central east Australia. To escape the heat in this dry area, these snakes shelter in abandoned burrows as well as cracks in rocks and dirt.
Size: Maxing out at 9.5 feet, this snake averages between 6 and 8 feet. Rather skinny, inland taipans weigh only about 5 pounds on average.
Description: With a shiny black head, and a pale to dark brown body with dark flecks, this species is identifiable by its mustard-yellow belly.
Diet: Inland taipans eat only mammals, and prefer plague rats or long-haired rats. These snakes use their venom to both kill prey and help digest it.
Fun Fact: This Australian snake is pretty shy and reclusive so it’s not a threat unless provoked.
2. Eastern Brown Snake
Binomial Name: Psuedonaja textillis
AKA: Common brown snake
Venom Detail: This snake’s venom includes several toxins, but life-threatening effects result from hemotoxins. About 5 mg of venom is delivered per bite, with reactions occurring in as little as two minutes.
Habitat: Native to central and eastern Australia, as well as southern New Guinea, brown snakes live pretty much anywhere except rainforests. Eastern brown snakes are most commonly found in woodlands and grasslands.
Size: This slender snake reaches about 7 feet in length.
Description: The underside is a creamy-yellow, while the body varies from pale brown to nearly black. Eastern brown snakes’ heads connect seamlessly to their bodies, without demarcation of a neck.
Diet: The house mouse is on this snake’s preferred menu, but it will happily dine on birds, frogs, and reptiles.
Fun Fact: Eastern brown snakes are responsible for the most snakebite deaths in Australia.
3. Coastal Taipan
Binomial Name: Ocyuranus scutellatus
AKA: Common taipan
Venom Detail: Each bite delivers an average of 120 mg of venom containing highly potent neurotoxins. Death occurs as quickly as 30 minutes, but typically around 2.5 hours after the bite.
Habitat: Coastal taipans live in fallen timber, abandoned burrows, and leaf piles. These homes are established in wet or dry forests, as well as savannah woodlands in coastal areas of northern and eastern Australia, as well as New Guinea.
Size: Weighing in at just 2 to 4 pounds, the average length is around 4 feet, but this venomous snake can surpass 6 feet including the tail.
Description: Usually a light olive to dark brown, coastal taipans are sometimes dark gray. The face is lighter, the eyes are red, and the belly is cream-colored with orange and pink flecks.
Diet: Coastal taipans eat mammals and birds, including small rodents and bandicoots.
Fun Fact: Despite the name, most coastal taipans actually live pretty far inland.
4. King Cobra
Binomial Name: Ophiophagus hannah
Venom Detail: Containing neurotoxins and cytotoxins, one bite can deliver as much as 420 mg of venom. Severe envenomation can lead to cardiovascular failure in just 30 minutes.
Habitat: Native to to Southeast Asia, China and India, king cobras live in plains and rain forests. King cobras’ colors vary based on where they call home.
Size: Adults reach lengths between 10 and 13 feet, with the longest measured surpassing 19 feet. The king cobra is the longest venomous snake in the world.
Description: Known for its large, oval hood, king cobras have olive green skin striped with white and black bands.
Diet: With a preference for other snakes, king cobras will also eat rodents, lizards, and other vertebrates.
Fun Fact: Due to habitat destruction, king cobras have been classified as vulnerable on the Red List of Threatened Species.
5. Black Mamba
Binomial Name: Dendroaspis polylepis
AKA: Scary snake is really the only other description for this deadly snake.
Venom Detail: Being rather shy, black mambas will typically escape confrontation. However, if cornered, a black mamba will raise a third of its body off the ground and attack repeatedly. Administering cardio- and neurotoxins with each bite, death occurs within about 20 minutes if left untreated.
Habitat: Native to southern and eastern Africa, black mambas live in savannas and rocky hills, taking shelter in rock and tree crevices. They live both on the ground and in trees.
Size: Second only to king cobras, black mambas reach lengths nearing 15 feet. The average, however, is closer to 8 feet. Full grown, these skinny snakes weigh in at around 5 pounds.
Description: The skin color on these snakes is typically olive or gray, and the inside of their mouths is a blueish-black color, hence the name.
Diet: With an occasional taste for birds, black mambas typically eat small mammals including rodents and squirrels.
Fun Fact: Reaching speeds of 12.5 miles per hour, these are some of the fastest snakes in the world. That’s about as fast as your average squirrel!
6. Saw-Scaled Viper
Binomial Name: Echis carinatus
AKA: Carpet viper
Venom Detail: Envenomation varies significantly, but it is estimated between 20 to 30 mg of hemotoxins are delivered with each bite. When not fatal, symptoms from this snake’s bite will persist for days or weeks.
Habitat: These vipers live in dry savannas north of the Equator. They are well-known in the desert regions of Africa and the Middle East, as well as southwestern Asia to India.
Size: Adults mature between 1 and 3 feet long.
Description: Saw-scaled vipers are recognized by pear-shaped heads and stout bodies covered with serrated scales.
Diet: Hunting at twilight, saw-scaled vipers look for mammals, birds, amphibians and invertebrates.
Fun Fact: These sidewinders rub their oblique scales against each other to produce a defensive hissing sound.
7. Eastern Diamondback Rattlesnake
Binomial Name: Crotalus adamanteus
AKA: woodland rattler, diamondback, and lozenge-spotted rattlesnake
Venom Detail: Average envenomation is between 400 to 450 mg, with the estimated lethal dose at just one-quarter of that. Due to anticoagulants in the venom, victims experience a mortality rate between 10%-30% if left untreated.
Habitat: Generally living in flatwoods and woodlands, these rattlers live throughout the southeastern U.S. However, one was found in New Jersey in 2020.
Size: The average length is 5.6 feet with a weight of 5 to 6 pounds, though a few stretching more than 8 feet long and weighing 15 pounds have been reported.
Description: Covered in a brownish to olive green color, this species is decorated by 24 to 35 dark diamonds outlined with yellowish scales.
Diet: These rattlers love small mammals, including rabbits, rice rats, and birds. Adults can easily consume a full-grown cottontail rabbit.
Fun Fact: The iconic rattle sound is the snake’s final warning to anyone or anything encroaching on its space.
8. Banded Krait
Binomial Name: Bungarus fasciatus
AKA: This snake is accepting recommendations for a new nickname.
Venom Detail: The amount delivered varies between 20 and 114 mg; severe envenomation can lead to respiratory failure due to the neurotoxins. Since contact with humans is rare, and defensive bites are thought to deliver low envenomation compared to predatory bites, mortality is below 10%.
Habitat: Inhabiting the entire Indo-Chinese subregion, banded kraits are most common in the states of eastern India. Banded kraits live in a variety of areas, including forests and farmlands.
Size: One of the longest kraits, these snakes reach lengths surpassing 7 feet. The average length is 5 feet, 11 inches.
Description: The alternating black and yellow crossbands make this snake easy to spot. It has a broad head with yellow markings and yellow lips.
Diet: Feeding mainly on other snakes, banded kraits also eat frogs, fish, and snake eggs.
Fun Fact: Banded kraits have been found at altitudes as high as 5,000 feet in Myanmar.
Venomous and Harmless Snakes in the U.S.
The CDC reports the most venomous snakes in the United States come from the Crotalidae family, including rattlesnakes, copperheads, and cottonmouths. Fortunately, less than 8,000 people are bitten by snakes each year in the U.S. And on top of that, the availability of antivenom means the odds of dying from a snake bite are nearly zero.
When in your own yard, you’re likely to cross paths with garter snakes and water snakes, of which there are dozens of species. All of these, fortunately, are harmless.
Regardless, snakes are one of Americans’ greatest fears, right above public speaking and heights.
The best thing to do when encountering snakes is to just leave them be. Most snakes (or most animals, for that matter) are unlikely to harm you unless they feel threatened.
If you have a serious snake problem, or think you might be dealing with some other dangerous pest, like venomous spiders, get expert help from a pest control professional near you.
Then, remember to tell your friends it was twice as big, three times as heavy, and at least slightly venomous. Be the hero of your own story, not that person who actually jumped, screamed, and ran for cover.
Main Photo Credit: King cobra / Rushen / Flickr / CC BY-SA 2.0