Snakes vs Spiders: Which is Deadlier to Humans?

Written by Patrick Sather
Published: April 8, 2022
© ROSA ROMERO HERRERA/Shutterstock.com
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Few animals fill people with fear as much as spiders and snakes. In fact, many people develop an extreme, overwhelming fear of snakes (arachnophobia) or spiders (ophidiophobia), and these fears are not completely irrational. Throughout the world, you can find snakes and spiders that produce enough venom to kill a person. Some are so deadly that a single bite could kill nearly a hundred grown humans. These fearsome creatures frequently prey on animals much larger than themselves and possess killer instincts. While most rarely act aggressively towards humans, they will attack if provoked or cornered. That said if we had to compare snakes vs spiders, which is deadlier?

To answer this question, we’ll first need to look at snakes and spiders as a whole. Then, we’ll identify what percentage of snakes and spiders possess the ability to kill a human and where they live. Finally, we’ll take a look at 3 of the most dangerous snakes and spiders in the world. Based on this information, we’ll determine which is deadlier to humans.

Comparing Snakes vs Spiders

Spider vs Snake
There are more than 3,000 species of snakes and 45,000 species of spiders

©ROSA ROMERO HERRERA/Shutterstock.com

There exist more than 3,000 snake species worldwide and nearly 45,000 known spider species. However, of these thousands of species, only a small fraction pose a real danger to humans. For example, around 600 snakes are capable of causing you serious injury, while only 200 can actually kill you. Meanwhile, although nearly all spiders are venomous you can only find about 30 species throughout the entire world that inflict a medically significant bite. That means that around 6.67% of snakes worldwide pose a real threat to humans. Similarly, less than one-tenth of 1 percent (0.06% to be exact) of spiders could potentially threaten a person’s life.

SnakesSpiders
Total Species3,00045,000
Species Capable of
Killing a Person
20030
Percentage of Species
Dangerous to Humans
6.67%0.06%
Most Venomous SpeciesInland Taipan SnakeSydney Funnel-Web Spider
Annual Deaths (US)<6<7
Annual Deaths (Worldwide)81,000 – 138,000Unknown

It’s worth mentioning that while venomous spiders can be found in almost every country on Earth, not every country or region is home to venomous snakes. After all, several countries do not have any native snakes including Iceland, Ireland, and New Zealand. Snakes also do not live in Alaska or the northern regions of Finland, Sweden, Norway, Russia, or Canada. However, although spiders are more widespread than snakes, snakes kill far more people each year than spiders. Scientists estimate that between 81,000 and 138,000 people worldwide die from snake bites each year. The majority of these deaths occur in countries in Africa and Asia where antivenom is less available. Case in point, in the United States fewer than 6 people per year die from snake bites.

On the other hand, the number of deaths attributable to spiders is less well known. Many countries do not keep good records of spider bite fatalities. In the United States, fewer than 7 deaths are attributable to spiders each year thanks to the widespread availability of antivenom. It can be assumed that worldwide spiders kill several hundred people each year but it’s impossible to say for sure.

3 of the Most Dangerous Snakes and Spiders

To continue our comparison of snakes vs spiders, we’ll now introduce you to 3 snakes and 3 spiders that pose a substantial threat to humans. This is not to say that these are the deadliest snakes and spiders in the world, merely that they are medically significant in their own way.

Most Dangerous Spiders: Black Widow Spider

Deadliest Animals in America
Although people often fear the black widow for its venomous bite, it is less deadly than many believe. A black widow’s bite can be harmful, but it is rarely fatal.

©Sari ONeal/Shutterstock.com

The black widow spider is one of the most feared and widely recognizable spiders in the world. It belongs to the genus Latrodectus which includes 34 different species of varying size and venom potency. Other notable widow spiders include the brown widow, red widow, Australian redback, and South African button spider. The black widow spider produces a neurotoxin that can cause latrodectism, the symptoms of which include muscle pain and spasms, cramps, excess sweating, elevated heart rate, and even death. That said, black widow spiders aren’t known to be aggressive, and fatalities are rare.

Most Dangerous Snakes: Saw-Scaled Viper

10 Most Venomous Animals - The Roman's Saw scaled Viper is the most dangerous snake in Africa and Asia
The saw-scaled viper reportedly kills more people than any other snake species.

©Luis Montero de Espinosa/Shutterstock.com

The saw-scaled viper is a small venomous snake in the genus Echis. It ranges throughout arid regions around the equator including Saudi Arabia, northern Africa, and India. Although it may not possess the most potent venom it is still regarded as one of the most dangerous snakes in the world. This is because it is a notoriously aggressive species that is very quick to strike if irritated. So, even though fatalities occur in only about 10% of bites if left untreated, the sheer number of bites makes the saw-scaled viper a very dangerous snake to encounter. In fact, it’s estimated that more people die each year from saw-scaled viper bites than from any other snake species.

Most Dangerous Spiders: Brazilian Wandering Spider

Biggest Spiders: Brazilian Wandering Spider
The Brazilian Wandering Spider is called “armed spiders” in Portuguese because their venom is a powerful weapon.

©Tacio Philip Sansonovski/Shutterstock.com

The Brazilian wandering spider holds the distinction of being considered the most venomous spider in the world, if not necessarily the most dangerous. A native to Central and South America, the Brazilian wandering spider gets its name from its habit of wandering the jungle floor at night in search of food. It is a relatively aggressive species and it is this trait in combination with its frequent presence in areas with a high population density that makes it particularly dangerous. As such, more people require hospitalization in Brazil due to its bite than any other spider. The bite of a Brazilian wandering spider can cause pain, increased blood pressure, sweating, fever, nausea, vomiting, and paralysis.

Most Dangerous Snakes: Forest Cobra

Deadliest Snake Bites - Forest Cobra (Naja melanoleuca)
The forest cobra delivers one of the largest venomous loads of any snake.

©NickEvansKZN/Shutterstock.com

The forest cobra is considered to be the second most deadly snake in the world and the world’s deadliest cobra in terms of its venom. While the Caspian cobra possesses more potent venom, the forest cobra far outstrips it in terms of venomous load. In a single bite, a forest cobra can deliver an average of 571 mg of venom and up to 1102 mg of venom. As such, the forest cobra possesses enough venom to kill nearly 65 people. Given this massive venom load, it’s no wonder that the forest cobra is considered the second most dangerous spider in the world in terms of sheer killing power.

Most Dangerous Spiders: Sydney Funnel-Web Spider

Most Venomous Spider
The Sidney Funnel-Web Spider has fangs longer than some snakes and can deliver a deadly bite.

According to many experts, the Sydney funnel-web spider is the most dangerous spider in the world. While its venom is not as potent as the Brazilian wandering spider it delivers a larger venom load per bite. In particular, it is the male Sydney funnel-web spider that is especially dangerous. The male Sydney funnel-web spider possesses venom that contains Robustoxin, which attacks the nervous system. As its name implies, you can only find the Sydney funnel-web spider in and around the city of Sydney. Its closeness to such a dense population center is another reason the spider is so deadly, as it means that spider bites are more common.

Most Dangerous Snakes: Inland Taipan Snake

fierce snake
The inland taipan (Oxyuranus microlepidotus) is the most venomous snake in the world.

©Alizada Studios/Shutterstock.com

The inland taipan is widely considered to be the most dangerous snake in the world and one of the most dangerous creatures in general. Also known as the western taipan or fierce snake it is only found in central east Australia. The inland taipan possess venom so toxic that it could kill over 100 grown humans, or 250,000 mice. Its venom contains a vile mixture of toxins including neurotoxins, hemotoxins, myotoxins, and possibly nephrotoxins. Luckily, the inland taipan rarely bites people unless provoked.

Final Thoughts on Snakes vs Spiders: Which is Deadlier to Humans?

fierce snake
Overall, snakes pose more a danger to humans than spiders.

©Ken Griffiths/Shutterstock.com

Given their small size, most spiders pose little threat to humans. The majority of spiders with potent venom rarely bite humans and even if they do they often do not deliver a large enough load for the bite to prove fatal. Typically, venomous spiders are only dangerous to very young children or adults with severely compromised immune systems. Meanwhile, although they are less widespread, there are more species of venomous snakes that pose a danger to humans. Additionally, due to their larger bodies and fangs, these venomous snakes present a substantial risk to humans given that they can deliver a much larger venomous load per bite. However, the majority of deaths occur in places where antivenom is scarce or completely unavailable. Still, it’s obvious that when it comes to snakes vs spiders, snakes are clearly much deadlier to humans.


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Spider vs Snake
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FAQs (Frequently Asked Questions) 

What are the most dangerous snakes in the United States?

There are around 30 species of venomous snakes in the United States. Of these, the majority of bites occur from copperheads, followed by rattlesnakes, then cottonmouths, and finally coral snakes. The most dangerous species include the Mojave rattlesnake, eastern diamondback rattlesnake, and coral snake.

What are the most dangerous spiders in the United States?

The most dangerous spiders in the United States include widow spiders, recluses, and yellow sac spiders. Widow spiders found in the United States include the northern, southern, eastern, and western black widows as well as the brown widow and red widow. Recluses found in the United States include the brown, Mediterranean, and Chilean recluses.

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