The term “wood spider” is not a specific scientific classification but a common name used across different regions for various large, conspicuous spiders found in forests, woodpiles, or near homes. This generalist term typically refers to species that are ground-dwelling hunters or those that build large webs in wooded environments. While any spider can bite if threatened, bites from species commonly labeled as wood spiders are rare and generally result in minimal medical consequence. These arachnids are not aggressive toward humans, and their venom is primarily designed for immobilizing small insect prey.
Identifying Spiders Commonly Called “Wood Spiders”
The spiders most often identified as wood spiders fall into three major families, each with distinct behaviors and appearances. Wolf Spiders, belonging to the family Lycosidae, are active, robust hunters that do not build webs to catch prey, instead relying on speed and camouflage in leaf litter or under logs. These spiders are terrestrial, often appearing gray, brown, or black with stripes, and can reach a body length of up to one inch, with females notably carrying their egg sac attached to their spinnerets.
Another frequent candidate is the Fishing Spider, genus Dolomedes, which are among the largest spiders in North America, sometimes reaching a leg span of three inches. Fishing Spiders prefer habitats near water but are commonly found on docks, in wood piles, or on the exterior of wooded structures. They can be distinguished by their long, slender legs and the ability to walk on the surface of water, hunting small aquatic organisms.
Large Orb Weavers, such as the Golden Silk Orb-Weaver, are also sometimes included in this group, recognized by the massive, intricate, circular webs they spin between trees or buildings. These spiders possess large, bulbous abdomens and are often brightly colored, but they are stationary web-builders. Unlike the hunters, orb weavers remain in their webs and rarely leave them, making accidental encounters and subsequent defensive bites far less likely.
Understanding Defensive Biting
Spiders do not bite humans for food, as people are not considered prey. Biting is a mechanism of last resort, used for self-defense when the spider perceives a threat to its survival. This defensive reaction is most often triggered when a spider is accidentally trapped against the skin, such as being rolled over in bedding, crushed inside clothing, or grabbed.
Spiders manage their venom strategically, as it is a valuable resource. In a defensive encounter with a large threat, the spider may choose to deliver a “dry bite,” injecting no venom at all to conserve the substance. Even when venom is injected, it is primarily neurotoxic or cytotoxic to smaller insects, and the minute quantity delivered is insufficient to cause serious harm to a human.
What to Expect from a Non-Venomous Bite
A bite from a common wood spider, such as a wolf spider or fishing spider, is comparable to a bee sting or a mosquito bite. Common symptoms include localized pain, mild swelling, and redness at the puncture site. These symptoms are a normal inflammatory response and typically subside within a few hours to a couple of days.
Initial care involves washing the area thoroughly with mild soap and water to prevent secondary bacterial infection. Applying a cool compress or ice pack can help reduce pain and swelling, and an over-the-counter pain reliever may be taken. A person should seek medical attention if symptoms worsen or spread. Warning signs include a rapidly expanding rash, signs of an allergic reaction like facial swelling or difficulty breathing, or if symptoms do not begin to improve after 48 hours.