10 Most Dangerous Spiders in the World

Arachnophobia (the fear of spiders) affects around 5% of the population including celebrities as diverse as Justin Timberlake and JK Rowling. Whilst both statistically and factually there is very little to fear from most spiders these little eight-legged critters do seem to have reserved a special place in the human psyche.

It is true that all spiders, by their definition, posses a pair of fangs through which they inject venom. And it probably doesn’t help their cause that they feed by turning their prey’s insides to liquid and then sucking it up.

However, it is also the case that only a tiny fraction of the more than 40,000 species of spider pose any real danger to humans. For starters most are too small to be able to puncture the skin and the vast majority are not in the least aggressive. Even those spiders that can bite rarely cause injuries worse than a mosquito bite. It is estimated that during the whole 20th century spiders were responsible for in the region of only 100 deaths globally.

That said, we are now going to look at those spiders that are considered dangerous to humans and have proven capable of inflicting significant injury. If you have seen our list of the deadliest Australian spiders you will be familiar with several of these already although the deadliest spider of them all is not from Australia at all.

10. Hobo Spider (Tegenaria agrestis)

Hobo spider (Tegenaria agrestis)

Hobo spider (Tegenaria agrestis) Photo: © tup wanders / License

The actual danger the hobo spider presents to humans is somewhat debatable. It has been proven to deliver quite serious bites to lab animals and there are many alleged cases of bites from these spiders causing necrosis, similar, but less severe than that observed in brown recluse bites. These bites cause an open wound whihc may take many weeks to heal.

There are two reasons the hobo spider has made it onto this list; firstly it is aggressive and fairly common, which increases the chance of an actual bite occurring. In fact the hobo spider is sometimes referred to as the ‘aggressive house spider’, although this could stem from a misinterpretation of its Latin name T. agrestis.
The other reason I’ve included this spider on the list is just because it is quite interesting that this spider only recently arrived in North America. Previously it was common throughout Europe and went practically unnoticed. Where it differs is that in Europe the hobo spider is not found in houses – other bigger, meaner house spiders keep it out!

9. Camel Spider (Solifugae)

Camel spider

Camel spider (Solifugae) Photo: Silver1 / License

The camel spider really is the stuff of nightmares. The biggest is the Egyptian giant solpugid with a body reaching up to six inches (15cm) in length and powerful jaws making up about a quarter of that this would be one of the biggest, scariest looking spiders in the world, except for one thing – it isn’t a spider, or a camel for that matter. Camel spiders are in fact a type of arachnid known as solifuges, which literally translates as ‘flee from the sun’. Also known as wind scorpions and sun spiders, solifuges are found in deserts throughout the world.

So why is the camel spider in the list at all? Well basically just because they look so fierce and grow so big. They are also lightning fast and capable of running at speeds of up to 10 mph (16 kph). Solifuges can inflict a painful bite but they are not venomous. So those stories about them crawling under camels, disemboweling camels and eating the insides might just be a little bit of an exaggeration!

 8. Yellow Sac Spider (Cheiracanthium)

Yellow Sac Spider

Yellow Sac Spider (Cheiracanthium) Photo: ©Micha L. Rieser / License

Small and innocuous in appearance  but capable of delivering quite a nasty bite, the yellow sac spider is one to avoid. The spiders of the Cheiracanthium family are usually between 5 and 10mm (1/4 to 3/8 ins) long and are pale yellow or green in colour. They are fairly widespread occurring from Australia to Canada and many places in between.

The venom of the yellow sac spider is a cytotoxin, which means it breaks down cells, possibly causing necrosis. Bites are characterized by an initial stinging pain followed by redness and swelling which can develop into a blister or sore.  The bite is often compared to that of the brown recluse, although it is less severe and any resulting wound is likely to heal much faster. Some experts reckon that many recorded brown recluse bites are in fact sac spider bites and that these spiders are responsible for more bites than any other species.

7. Fringed Ornamental Tarantula (Poecilotheria)

Fringed ornamental tarantula

Fringed ornamental tarantula (Poecilotheria) Photo: © Ameng Wu

Tarantulas – the archetypal big hairy spiders that have been the terror of arachnophobes since time began. The name comes from a Spanish dance, which apparently is how people jumped around when bitten by one of these critters. Unlike the smaller spiders on this list tarantulas are mygalomorphs, which means their twin fangs point downwards and have to be stabbed into the prey, rather than the pincer like action of most smaller species.

But everybody knows that despite their terrifying demeanor, tarantula bites aren’t so bad, right? Well it may be true that most tarantula bites are no worse than a bee sting, however the Poecilotheria genus of spiders are renown for having a particularly nasty bite, none more so than Poecilotheria ornata – the fringed ornamental tarantula. The bite from one of these is reported to have caused excruciating pain, and extreme muscle cramping in some cases. One bite victim ended up in the emergency room after experiencing severe spasm and chest pains.
So whilst there have been no confirmed fatalities from this tarantula it certainly carries a potent venom and injects it by the bucket load.

6. Mouse Spider (Missulena)

Mouse spider

Photo: Bruiser15 License

At this point we encounter our first Australian spider and the bites become that bit more medically significant. There are around 12 species of mouse spider in Australia and there name comes from their soft furry abdomens and not from the fact they might eat mice, although I’m sure they would. Armed with huge fangs and a venom that is similar to that of the deadly Sydney funnel-web spider this spider is every bit as dangerous as it looks.

Whilst the mouse spider is potentially dangerous it is far less aggressive than the Sydney funnel-web plus it often gives ‘dry bites’, i.e. without venom. Therefore it appears lower on this list than its meaner cousin.