The huntsman spider, a member of the family Sparassidae, is known globally for its intimidating size and startling speed. Despite its fearsome appearance, the answer to whether this arachnid is dangerous is generally reassuring. Huntsman spiders are found across tropical and temperate regions worldwide, making encounters relatively common. While they can be very large, they are not typically considered medically dangerous to people.
Assessing the Medical Risk
A bite from a huntsman spider is rare and usually occurs only when the spider feels trapped or is guarding an egg sac. The venom, which the spider uses to immobilize its insect prey, is of low toxicity to humans and not medically significant for healthy individuals. Huntsman venom is not known to cause systemic poisoning or life-threatening effects.
A bite can be painful due to the spider’s relatively large fangs and the mechanical puncture of the skin. Localized effects typically involve mild to moderate pain, redness, and swelling at the site of the bite. These symptoms usually subside quickly, often within a few hours.
In some instances, mild generalized symptoms may develop, such as a slight headache, nausea, or an irregular pulse rate. Severe allergic reactions are extremely uncommon but, as with any spider bite or insect sting, they can occur in hypersensitive individuals. A huntsman spider bite is a localized injury that rarely requires medical intervention beyond basic first aid.
Identifying the Huntsman Spider
Huntsman spiders can be distinguished from other arachnids by their impressive size and the unique orientation of their legs. They are generally brown or gray, sometimes with subtle banded markings on their legs, and possess a hairy appearance that can lead to misidentification as a tarantula. The leg span of larger species can reach up to 15 centimeters, though the giant huntsman spider found in Laos can have a span of up to 30 centimeters.
A defining characteristic is their flattened body shape, which allows them to hide effectively in narrow crevices and under loose bark. Their eight legs are “laterigrade,” meaning the joints are twisted so the legs extend forward and laterally, giving them a distinct, crab-like stance. This leg structure is an adaptation for their speed and agility as active hunters, which is why they are sometimes called giant crab spiders.
Unlike other spiders, huntsmen do not construct webs to capture food; instead, they actively stalk and chase down prey like insects and small lizards. They rely on speed and strength to subdue their meals. When identifying a huntsman, look for a large, flat, fast-moving spider that is not sitting in a web.
Habitat and Common Encounters
In their natural environment, huntsman spiders prefer protected spaces like under loose tree bark, beneath rocks, or in rock wall crevices. Their flattened body is perfectly suited for squeezing into these tight, secure daytime retreats. They are primarily nocturnal, emerging at night to hunt for food.
Human encounters often happen when the spiders seek shelter from extreme heat or cold, leading them to enter sheds, garages, or houses. They are frequently found high up on walls or ceilings, where their excellent grip allows them to move with surprising speed. The spider’s characteristic behavior of moving extremely fast is often misinterpreted as aggression.
A huntsman running directly toward a person is usually a panicked reaction, as the spider is trying to flee a perceived threat and has poor vision for distance. These spiders are also notorious for hiding in cars, sometimes being found behind sun visors or dashboards, drawn to the dark, sheltered spaces. The best way to manage an encounter is to remain calm and allow the spider to move away, or to use a container to catch and release it outside.