Wolf spiders: Behavior, bites and other facts
To see a size and visual comparison of wolf spiders and brown recluse spiders, check out this graphic from the University of Nebraska–Lincoln (opens in new tab) , which highlights the differences between the two types of spider, as well as other species that can be confused with brown recluse spiders. To learn more about Desertas wolf spiders, a critically endangered species, and what Bristol Zoological Society and other groups are doing to save them, check out the organization’s Desertas Wolf Spider Conservation Strategy (opens in new tab) . To see how wolf spiders move, watch this short YouTube video by the Billings Gazette (opens in new tab) , a Montana-based newspaper.
Are Wolf Spiders Poisonous?
More than 200 species of wolf spiders are native to North America, so it’s likely that you’ve encountered this eight-legged creature at one time or another.
These spiders have earned their name due to their tendency to stalk their prey before capturing them. True “lone wolves” among spiders, these solitary arachnids live and hunt on their own. In fact, they do not socialize with other wolf spiders unless it’s mating season (fall). Yet, while wolf spiders may be an intimidating threat to other insects, are they dangerous to people?
Wolf spiders are not poisonous. But they are venomous. There is a difference. However, that does not necessarily mean they are of much danger to humans. Wolf spiders produce a venom designed to paralyze their prey (normally a small crawling insect), but, in the case of the wolf spider, this venom is not especially toxic to human beings. Generally speaking, a wolf spider bite is no more dangerous or painful than a bee sting. Typical reactions to a wolf spider bite include initial pain and redness, but both symptoms gradually subside in most people. In fact, medical histories hold no records of serious consequences resulting from a wolf spider bite. On rare occasions, however, people have been known to have an allergic reaction.
Do Wolf Spiders Bite?
Wolf spiders bite, but they don’t often bite humans. When threatened, these spiders prefer to retreat. Wolf spider bites are most likely to occur if you are directly handling one or should one become trapped next to your skin.
How Big Are Wolf Spiders?
Wolf spiders come in many sizes and can grow to be quite large. They range from a quarter of an inch to about one and a half inches in length.
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Because they are often brown, wolf spiders are sometimes confused with the brown recluse spider. However, wolf spiders do not sport the characteristic, violin-shaped marking that brown recluses do. Wolf spiders do have leg band markings, which brown recluse spiders do not have. If you spy a large, dark, fast-moving spider scurrying across your floor, it’s likely a wolf spider.
Where Are Wolf Spiders Found?
Wolf spiders can be found worldwide. They commonly live in grasslands and meadows, but they may also live in mountains, rainforests, wetlands and deserts. Some wolf spiders hide in vegetation or fallen leaves while others burrow in soil, or build tunnels under – or between – boards, stones, firewood and even your home’s siding.
Wolf spiders may also venture into homes in the fall when they’re looking for a warm place to spend the winter and raise their young. In domestic environments, they can often be found around houseplants, doors, windows, basements and in garages. However, you won’t be able to detect the presence of wolf spiders by looking for webs. Wolf spiders produce silk, but mostly for the purpose of creating egg sacs. They are nocturnal hunters that usually only come out of hiding after sunset to pursue and ambush their prey.
Related > Spider Eggs in the House: What Do You Need to Know?
What Should You Do If You See a Wolf Spider?
To help avoid being bitten, refrain from touching or picking up a wolf spider. You should also avoid squishing it as doing so may cause the release of hundreds of spiderlings.
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Wolf spiders: Behavior, bites and other facts
Wolf spiders are a family of mostly large, hairy and athletic arachnids. Rather than catching their prey in webs, wolf spiders chase it down similar to the way a wolf does, although these spiders hunt alone, not in packs.
There are nearly 2,400 wolf spider species across 125 genera, according to the Integrated Taxonomic Information System (opens in new tab) (ITIS). They live around the world and are found throughout the U.S. Wolf spiders are especially common in grasslands and meadows, but they also live in mountains, deserts, rainforests and wetlands — anywhere they can find insects to eat, according to the University of Michigan’s BioKids (opens in new tab) website.
What do wolf spiders look like?
Wolf spiders are usually brown, gray, black or tan, with dark markings — most commonly stripes, according to the Missouri Department of Conservation (opens in new tab) . Their coloring is effective camouflage, helping them catch their prey and hide from predators. Wolf spiders’ size varies, and their body lengths range from about a quarter of an inch (0.6 centimeter) to over an inch (3 cm) long, not including their legs. The Desertas wolf spider (Hogna ingens) from Deserta Grande Island in the Atlantic Ocean is one of the largest wolf spiders and has a leg span of 4.7 inches (12 cm), according to the Bristol Zoological Society (opens in new tab) in England. Female wolf spiders are typically larger than males.
Wolf spider taxonomy
Kingdom: Animalia
Phylum: Arthropoda
Class: Arachnida
Order: Araneae
Family: Lycosidae
Wolf spiders have a “distinctive eye arrangement, where the front or anterior row is composed of four small eyes of roughly the same size arranged in almost a straight row,” said Jo-Anne Nina Sewlal, an arachnologist at the University of the West Indies in Trinidad. (Sewlal spoke with Live Science in 2014 and died in 2020.) “The back or posterior row is arranged in a V-pattern with the apex next to the anterior row.” Wolf spiders have excellent night vision and primarily hunt in the dark. “They are also quite easily detected at night due to their eyeshine,” Sewlal said.
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Are wolf spiders dangerous?
Wolf spiders can bite if threatened, but their venom doesn’t pose a serious danger to humans. According to Penn State’s College of Agricultural Sciences (opens in new tab) , wolf spiders bite humans when they are mishandled or trapped next to the skin. Bite victims may exhibit some redness or swelling, but no serious medical problems caused by a wolf spider bite have ever been reported. However, wolf spider bites can be very painful, so these critters shouldn’t be picked up by hand, the University of Kentucky’s Department of Entomology (opens in new tab) notes.
Brown wolf spiders can be confused with more venomous brown recluse spiders, especially in houses. Fast-moving spiders on the ground are more likely to be wolf spiders, as brown recluse spiders are very rarely seen out in the open, according to the University of Kentucky. People can tell the spiders apart using size and banding patterns; wolf spiders are usually larger and have banding patterns on their legs, which are absent on brown recluse spiders. Anyone who has been bitten by a brown recluse spider should seek emergency medical attention, according to MedlinePlus (opens in new tab) , a service of the National Library of Medicine.
Habitat and feeding
Wolf spiders are solitary animals that typically roam alone in the night, stalking prey. They are “mostly nocturnal and often mistaken for tarantulas,” Sewlal said. These spiders spend most of their time on the ground, but they can climb trees or other objects if they need to. Their habitats include stream edges, gravel and low vegetation, according to the Missouri Department of Conservation. Wolf spiders sometimes find their way into houses, usually in basements, crawl spaces and breezeways after they enter near ground level, according to Michigan State University’s Plant & Pest Diagnostics (opens in new tab) .
Wolf spiders eat mostly ground-dwelling insects, such as crickets and other spiders. Large females may take on small amphibians and reptiles, according to BioKids. Some species chase down and seize their prey, while others wait for prey to walk by and then ambush it. Wolf spiders often jump on their prey, hold it between their legs and roll over on their backs, trapping their prey with their limbs before biting it and injecting their venom.
Wolf spiders use their keen eyesight, camouflage, speedy movements and high sensitivity to vibrations to help them avoid predators such as lizards, birds and hunting wasps. According to the Smithsonian (opens in new tab) , hunting wasps paralyze wolf spiders with a sting, drag them back to burrows and lay eggs in them so larvae hatching from the eggs have something to eat.
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Mating
Female wolf spiders leave scent markings so males can find them to mate. When a male locates a female, they perform a courtship ritual in which the male signals to the female by waving its legs and pedipalps (short, sensory appendages near their mouths), according to the Australian Museum (opens in new tab) in Sydney. After mating, female wolf spiders lay several dozen or more eggs and wrap them in silk, creating an egg sac.
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“Female wolf spiders carry their egg sacs attached to her spinnerets [at the tip of their abdomens where silk is produced],” Sewlal said. Mothers are known to exhibit aggressive behavior when carrying their egg sacs. They sometimes need to drop their egg sacs to more easily escape predators. If this happens, females will search furiously to find them again and may even pick up another wolf spider’s abandoned egg sac to care for. A 2021 study published in the journal Ethology (opens in new tab) found that Pardosa milvina, a common North American wolf spider, can recognize its own egg sacs and is less likely to pick up those of unrelated spiders when given a choice. However, the spiders in the study cared for unrelated eggs as if they were their own when they did pick them up.
Wolf spiders’ maternal behavior doesn’t stop with the egg sacs. “After hatching, the spiderlings climb on their mother’s back, and she carries them around for several days,” Sewlal said. After this, the spiderlings leave their mothers and go off alone. Male wolf spiders typically live for one year or less, while females can live for several years.
Additional resources
To see a size and visual comparison of wolf spiders and brown recluse spiders, check out this graphic from the University of Nebraska–Lincoln (opens in new tab) , which highlights the differences between the two types of spider, as well as other species that can be confused with brown recluse spiders. To learn more about Desertas wolf spiders, a critically endangered species, and what Bristol Zoological Society and other groups are doing to save them, check out the organization’s Desertas Wolf Spider Conservation Strategy (opens in new tab) . To see how wolf spiders move, watch this short YouTube video by the Billings Gazette (opens in new tab) , a Montana-based newspaper.
Bibliography
Berry, A. D. & Rypstra, A. L. “Egg sac recognition and fostering in the wolf spider Pardosa milvina (araneae: lycosidae) and its effects on spiderling survival,” Ethology, Volume 127, Jan 29, 2021. https://onlinelibrary.wiley.com/doi/abs/10.1111/eth.13134
BioKids, Animal Diversity Web, University of Michigan, “Lycosidae,” 2001. http://www.biokids.umich.edu/critters/Lycosidae/
Blake Newton, University of Kentucky Department of Entomology, “Wolf Spiders,” updated Jan. 30, 2008. https://www.uky.edu/Ag/CritterFiles/casefile/spiders/wolf/wolf.htm
College of Agricultural Sciences, The Pennsylvania State University, “Wolf Spiders,” updated Dec. 10, 2018. https://extension.psu.edu/wolf-spiders
Medline Plus, National Library of Medicine, “Brown recluse spider,” updated Feb. 18, 2022. https://medlineplus.gov/ency/article/002859.htm
Plant & Pest Diagnostics, Michigan State University, “Wolf Spider,” May 19, 2020. https://www.canr.msu.edu/resources/wolf-spider
This article was originally published on Dec. 25, 2014. It was updated on March 7, 2022, by Live Science staff writer Patrick Pester.
