Huntsman spiders are large, fast spiders that live in warm climates throughout the world. They are named for the way that they catch their prey.

Unlike many spider species, huntsman spiders "don't build webs to catch prey," said Christy Bills, an entomologist and the invertebrate collections manager at the Natural History Museum of Utah. Instead, these spiders hunt down their prey.

There are thousands of subspecies in this family (Sparassidae). The average huntsman spider species is about 1 inch (2.5 centimeters) long with a leg span of up to 5 inches (12.7 cm), according to a 2009 article in the journal Biodiversity and Conservation. The giant huntsman spider (Heteropoda maxima), however, has a leg span of up to 12 inches (30 cm), making it the largest spider by diameter, according to the Proceedings of the Royal Society B (2017). It is often described as being "the size of a dinner plate." (The largest spider by weight is probably the goliath birdeater tarantula (Theraphosa blondi), according to the American Association for the Advancement of Science.)

Peter Jäger, head of the arachnology department at the Senckenberg Research Institute in Frankfurt, Germany, discovered the giant huntsman in a cave in Laos in 2001, according to his research published in the journal Zoosystema. Only a few people in the world have seen this behemoth arachnid.

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What do huntsman look like?

Because of their size, huntsman spiders are sometimes incorrectly identified as tarantulas. One way to tell a huntsman from a tarantula is by the position of the creature's legs. Most spiders' legs bend vertically under the body. "Huntsman spiders usually have legs that are splayed out to the sides, crablike," Bills said. In fact, huntsman spiders are also referred to as giant crab spiders.

Huntsman spiders' legs have twisted joints, which allow the appendages to extend forward like a crab's and their alignment allows the spider to move side-to-side, also similar to a crab. Males have longer legs, although females have larger bodies. "Colors and patterns vary," Bills said. The spiders' legs are typically gray or brown, and banded.

Many huntsman species' bodies have a flattened appearance, ideal for squeezing into tight places, according to the Australian Museum.

Classification/taxonomy

According to the Integrated Taxonomic Information System (ITIS), the taxonomy of giant huntsman spiders is:

Kingdom: AnimaliaSubkingdom: BilateriaInfrakingdom: ProtostomiaSuperphylum: EcdysozoaPhylum: ArthropodaSubphylum: ChelicerataClass: ArachnidaOrder: AraneaeFamily: SparassidaeGenus & species: Heteropoda maxima

Where are they found?

The giant huntsman was found in Laos, and most huntsman species are native to Asia. They are also prevalent in Africa, Australia and South America, according to Science Alert. They live in some warm American states such as Florida, California and Texas, and, according to the University of Florida, it is presumed that they were introduced from Asia. Folklore stories claim the spiders traveled from Asia in boxes of bananas, and because of that, they are sometimes called banana spiders.

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What environment do they live in?

Bills extolled the huntsman's speed: "They can often be quite large and very quick." In fact, the huntsman spider can move up to a yard (almost 1 meter) a second, she said. The spider typically lives under loose bark on trees, under rocks, in crevices and under foliage. Huntsman spiders, especially Australian species, are notorious for entering houses and cars. According to the Australian Museum, they have been "found hiding behind sun visors or running across the dashboard." These spiders can be social, and dozens will sometimes sit together on dead trees or stumps.

What do huntsman spiders eat?

The huntsman runs after or ambushes its prey, killing it with venom and strong mouthparts, called the chelicerae. Once captured, the prey will be injected with deadly venom from glands within the spider's body, according to the University of Florida. The huntsman can also be a valuable spider because it eats cockroaches, in addition to other spiders and domestic insect pests.

Are huntsman spiders dangerous?

Huntsman are not deadly to humans. According to the Australian Reptile Park, although huntsman spiders are venomous and their bites can be painful to humans, they do not cause anything more serious than mild nausea or headaches. Usually localized swelling and pain are the only symptoms of a huntsman spider bite.

In most instances, a huntsman spider will attempt to run away from a human, rather than biting them, according to the Australian Museum. However, the females of these spiders are more likely to bite when they perceive a threat to their young.

In the event that someone does get bitten, they should try to remain as calm as possible. This is to prevent their heart rate from increasing and spreading the venom more quickly around the body. Applying an ice pack can reduce the pain caused by the bite, but a pressure immobilisation bandage is not needed, according to Australia Wide First Aid.

How do huntsman reproduce?

Compared to other spider species that eat their mates, huntsman spiders are downright romantic. According to the Australian Museum, their mating ritual can last for several hours and involves lengthy caresses and other demonstrations of interest. The male drums his pedipalps — antennae-like appendages near the mouth — against tree trunks before inserting them into the female to fertilize her eggs.

After mating, the female lays up to 200 eggs and encases them in a large, oval, spun-silk sac. "Some huntsmans are dedicated mothers," Billa said. They "look after their egg sacs, guarding them fiercely."

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According to the University of Florida's Entomology and Nematology Department, some females carry the sac with them under their bodies, which severely restricts their movements. Others place the sac under a rock or piece of bark and stand over it, without eating, for up to three weeks. In both cases, females may become aggressive when guarding their egg sacs.

According to the Australian Reptile Park, at birthing time, the mother may tear the egg sac open to help her spiderlings emerge. She'll then stay with the babies for several weeks. Baby huntsmen are pale in color and darken with each molt. Huntsman spiders can live for more than two years.

Additional resources

Learn more about the giant huntsman at the Encyclopedia of Life.Here is a handy guide to identifying huntsman spiders and other arachnids Check out the World Spider Trait database for more information and research about spiders from around the world This article was updated on Aug. 11, 2021 by How It Works staff writer Ailsa Harvey.