Brazilian wandering spider. Photo by Techuser.
Brazilian wandering spider. Image: Techuser.

With their pupil-less eyes, hairy legs, and biting fangs, spiders strike fear into the hearts of many people. But is their bad reputation deserved?

Not really — spiders are generally no more dangerous than the countless other animals you find outside, and they typically only bite when provoked. Nevertheless, there are some truly enormous spiders out there that will frighten even the most battle-hardened adventurer. Let’s have a look at them…

Wolf Spiders

Wolf spider with grasshopper. Photo by Gecko gr.
Wolf spider with grasshopper. Photo by Gecko gr.

Wolf spiders are not a single species of spider, but an entire family. Many of these guys become quite large; The Carolina wolf spider is the biggest of all, growing to 1.4 inches in length.

Despite their fearsome name and appearance, wolf spiders are harmless to humans, and they don’t possess venom powerful enough to cause damage. They get their name from their tendency to wander in search of prey, rather than build webs to capture it.

Brazilian Wandering Spiders

Brazilian wandering spider. Photo by João P. Burini.
Brazilian wandering spider. Image: João P. Burini.

Brazilian wandering spiders are spiders in the genus Phoneutria, and they are not only the most venomous spiders in the world but also among the biggest of all venomous spiders. In fact, they are the largest known araneomorphs, aka “true spiders”. They can grow up to 2 inches in length and have leg spans that reach about 6 inches.

This can make for a particularly frightening combination, but since venom production expends so much time and energy (and since venom is required to immobilize prey), Brazilian wandering spiders rarely deliver a full dose of venom. Yet, when they do bite a human, the effects are quite severe, no matter the dosage.

Within 30 minutes of a Brazilian wandering spider bite, a host of horrible symptoms will rear their ugly heads. High/low blood pressure, fast/slow heartbeats, nausea, abdominal cramping, hypothermia, vertigo, blurred vision, convulsion, and excessive sweating associated with shock can all occur. But wait, there’s more — male victims can experience a painful erection that lasts for hours.

Golden Silk Orb-Weavers

Golden orb-weaver spider with locust. Photo by Brian W. Schaller.
Golden orb-weaver spider with locust. Photo by Brian W. Schaller.

Golden orb-weaver spiders are among the largest of the araneomorphs. Growing up to 5 inches across, these massive arachnids have been documented capturing and devouring large vertebrates such as snakes, frogs, and even hummingbirds.

Fortunately, they are not aggressive towards humans, and their venom is not potent. In fact, they are rather welcome sights in gardens and farmlands, since they consume pests, such as locusts.

Tiger Spiders

Poecilotheria rajaei. Photo by Ranil Nanayakkara - British Tarantula Society.
Poecilotheria rajaei. Photo by Ranil Nanayakkara – British Tarantula Society.

Tiger spiders are not a single species of spiders; They’re actually a genus of arboreal tarantulas known as Poecilotheria. All of these species are quite large, growing up to 10 inches across.

Native to India and Sri Lanka, tiger spiders tend to yield more venom than other tarantulas, and their bites can be quite painful and significant. In Switzerland, a pet Indian ornamental tree spider (Poecilotheria regalis) bit a 45-year old man, and after experiencing severe muscle spasms and chest pains, the man had to go to the emergency room.

Brazilian Salmon Pink

Brazilian salmon pink. Photo by George Chernilevsky.
Brazilian salmon pink. Photo by George Chernilevsky.

The Brazilian salmon pink (Lasiodora parahybana) is one of the largest of all spiders. Growing up to 4 inches in length, having a leg span of 10 inches, and weighing up to 4 ounces, these spiders are huge, and they have an equally enormous appetite.

From insects to amphibians to reptiles to small birds, the Brazilian salmon pink spider has quite a wide range of dietary choices. They have even been known to prey upon common lanceheads, which are a species of highly venomous snake native to South America.

Despite their frightening diet, Brazilian salmon pinks do not possess venom that can harm humans, but they do have a painful bite. Yet, instead of biting potential predators, these tarantulas prefer to rub urticating hairs on their abdomen and release them into the air. These hairs contain microscopic barbs, which irritate the skin and eyes of any organism they touch. This is a defense mechanism commonly used by New World tarantula species.

Giant Huntsman Spider

Giant huntsman spider. Photo by Petra & Wilfried.
Giant huntsman spider. Photo by Petra & Wilfried.

The giant huntsman spider (Heteropoda maxima) has the largest leg span of all spiders. At 12 inches across, it would be hard to miss inside your home. In fact, due to their size, huntsman spiders are commonly misidentified as tarantulas — but they’re not nearly as bulky.

Like most of the spiders on this list, the giant huntsman looks more fearsome than it actually is. While venomous, it does not possess a bite that is harmful to humans and would rather run away than defend itself. But, even if it was dangerous, you probably will never see one in person, since giant huntsman spiders are native to the Asian country of Laos.

Goliath Bird-Eating Spider

Goliath bird-eating spider. Photo by Didier Descouens.
Goliath bird-eating spider. Photo by Didier Descouens.

Although the giant huntsman spider has the largest leg span of all spiders, the goliath bird-eating spider (Theraphosa blondi) is the largest of all spiders and beats the giant huntsman in every other category. Goliath bird-eating spiders can grow up to 4.7 inches in length, weigh up to 6 ounces, and have a leg span of 11 inches. So, essentially, they’re the size and weight of a fairly large potato.

Despite the fearsome name, Goliath bird-eating spiders rarely eat birds. Instead, they primarily eat earthworms, other arthropods, and occasionally mice and lizards. The “bird-eating” part of the name originates from an 18th-century engraving by Maria Sibylla Merian, who portrayed a related Theraphosa species devouring a hummingbird.

While they are huge and can have 1.5-inch fangs, Goliath bird-eating spiders are gentle giants that are not a threat to humans. They are mildly venomous, but their bites are not more dangerous than a wasp sting, and medical attention is rarely required. However, they do possess urticating hairs on their abdomen, which are quite itchy and can be released into the air to deter predators.