California is home to a wide variety of spiders, ranging from harmless household species to a few that carry a medical risk. With its diverse climates and ecosystems, the state supports both native and introduced spider species. While many people fear spiders, most are beneficial predators that help control insect populations. This guide explores 15 common spiders found across California, including how to identify them, where they live, their behavior, and whether they pose any danger to humans.
1. Black Widow Spider (Latrodectus hesperus)
The Black Widow is one of the most recognizable spiders in California, known for its potent venom and signature red hourglass marking. While it has a fearsome reputation, this spider is generally non-aggressive and bites only when threatened.
Identification
- Color: Shiny black body (females); males are lighter and smaller
- Marking: Distinct red or orange hourglass shape on the underside of the abdomen (females)
- Size: Females about 1.5 inches (including leg span); males are significantly smaller
- Web: Irregular, messy-looking webs, often found near the ground
Habitat
Black Widows favor dry, sheltered locations like garages, sheds, under decks, woodpiles, and even outdoor furniture. They prefer dark, undisturbed areas where they can spin their webs.
Behavior
These spiders are mostly active at night and prefer solitude. Females remain near their webs, especially when protecting egg sacs, and may bite in self-defense. Males usually roam in search of mates and are not known to bite.
Venom and Risk to Humans
The venom of a female Black Widow affects the nervous system and can cause severe discomfort, including muscle pain, cramps, and nausea. Fatalities are extremely rare, and medical treatment is effective if needed.
2. Brown Widow Spider (Latrodectus geometricus)
Often mistaken for its more dangerous cousin, the Brown Widow is a venomous spider found throughout California. It is less aggressive than the Black Widow and usually hides in secluded outdoor areas.
Identification
- Color: Light to dark brown or tan with an orange or yellow hourglass on the underside
- Marking: Geometric patterns or mottled appearance on the body
- Size: Slightly smaller than the Black Widow; females up to 1 inch with legs extended
- Web: Similar messy web as the Black Widow, usually in outdoor furniture or under eaves
Habitat
Brown Widows thrive in urban environments and are commonly found in outdoor furniture, mailboxes, fences, under railings, and corners of buildings. They prefer dry and protected areas.
Behavior
These spiders are less reclusive than Black Widows but are still non-aggressive. Females stay near their web and may deliver a defensive bite if threatened. Males are small, harmless, and rarely seen.
Venom and Risk to Humans
Brown Widow bites are generally less severe than Black Widow bites. Symptoms may include localized pain, redness, or swelling. Serious complications are rare, and most bites heal without medical treatment.
3. Western Black-legged Spider (Steatoda grossa)
Often called the “false widow,” this spider resembles the Black Widow but is far less harmful. It is common indoors and outdoors across California and plays a helpful role in pest control.
Identification
- Color: Dark brown to purplish-black
- Marking: No hourglass; sometimes has light striping or faint pattern on abdomen
- Size: Around 0.5 inches long (not including legs)
- Web: Tangles webs in dark corners, baseboards, or closets
Habitat
This spider is adaptable and can be found inside homes, basements, garages, or sheds. Outdoors, it hides under rocks, boards, or debris. It prefers low-light, undisturbed environments.
Behavior
Western Black-legged Spiders are shy and retreat when disturbed. They prey on insects and other spiders, including Black Widows, making them beneficial in homes and gardens.
Venom and Risk to Humans
Although it has venom, its bite is typically mild to humans. It may cause slight irritation or a small red bump. Often confused with dangerous species, it poses little real threat.
4. Desert Recluse Spider (Loxosceles deserta)
The Desert Recluse is one of the few potentially dangerous spiders in California. It belongs to the recluse family and is found in the drier regions of Southern California and desert areas.
Identification
- Color: Tan to light brown
- Marking: Faint violin-shaped mark on the cephalothorax (head area)
- Size: Body about 0.5 inches long; leg span up to 1.5 inches
- Web: Irregular, loosely constructed web in hidden, sheltered spots
Habitat
Desert Recluses inhabit dry, undisturbed environments like sheds, garages, woodpiles, and debris. Outdoors, they live under rocks, bark, or desert vegetation. They are rarely found indoors in heavily populated areas.
Behavior
These spiders are nocturnal and prefer solitude. They do not build webs to catch prey but instead hunt at night. If disturbed or trapped against the skin, they may bite defensively.
Venom and Risk to Humans
The bite of a Desert Recluse can lead to necrotic skin lesions in rare cases. Reactions vary by individual and range from mild irritation to ulcerating sores. Immediate medical attention is recommended for suspected bites.
5. Chilean Recluse Spider (Loxosceles laeta)
Native to South America, the Chilean Recluse has been introduced to California and is rarely seen but potentially dangerous. It is considered more venomous than other recluse species.
Identification
- Color: Light to dark brown
- Marking: Pronounced violin-shaped marking on the cephalothorax
- Size: Body length up to 0.75 inches; leg span can exceed 2 inches
- Web: Minimal and irregular, typically found in hidden indoor spaces
Habitat
Chilean Recluses are occasionally found in older buildings, attics, closets, or behind furniture. They prefer dark, undisturbed areas and are more commonly reported in Southern California.
Behavior
These spiders are extremely shy and avoid humans. They come out at night to hunt for insects. Like other recluse spiders, they do not use webs to trap prey.
Venom and Risk to Humans
The bite of a Chilean Recluse can be severe, potentially leading to skin necrosis and systemic symptoms. However, bites are rare, and the spider typically avoids human contact.
6. California Trapdoor Spider (Bothriocyrtum californicum)
This elusive spider is native to California and is known for building burrows with camouflaged “trapdoors.” Though it looks intimidating, it is non-aggressive and rarely encountered.
Identification
- Color: Dark brown to black, with a shiny appearance
- Marking: No distinct markings; robust and hairy body
- Size: Body about 1 to 1.5 inches long
- Web: No web for trapping prey; builds silk-lined burrows with a hinged door
Habitat
California Trapdoor Spiders live in hilly or forested areas, especially in moist soil. They build burrows in the ground, often along trails or under rocks, with a silk-hinged door that blends in with the surroundings.
Behavior
They spend most of their lives in burrows, emerging only at night to ambush prey. These spiders are extremely reclusive and pose no threat unless provoked.
Venom and Risk to Humans
Their venom is mild and not dangerous to humans. A bite may cause temporary pain or redness but is not medically significant.
7. California Turret Spider (Antrodiaetus riversi)
This fascinating spider is known for its turret-like burrow entrances and is native to Northern California. It resembles tarantulas but is smaller and less commonly seen.
Identification
- Color: Reddish-brown to dark brown
- Marking: No specific markings; smooth, glossy cephalothorax and hairy abdomen
- Size: About 1 inch long
- Web: No traditional web; creates turret-shaped burrow entrance made of silk and debris
Habitat
California Turret Spiders are found in damp, forested regions, especially along stream banks and under leaf litter. They construct vertical burrows with a turret that sticks above the ground.
Behavior
These spiders are rarely seen outside their burrows. They wait at the turret’s edge at night to catch insects. They are very shy and withdraw quickly when disturbed.
Venom and Risk to Humans
Their bite is not dangerous to humans. They are more of a curiosity than a threat, and bites are extremely rare.
8. Wolf Spider (Hogna spp.)
Wolf Spiders are fast-moving hunters found throughout California. While their appearance can be intimidating, they are not aggressive and are helpful in controlling insect populations.
Identification
- Color: Brown to gray with darker markings or stripes
- Marking: Distinct eye pattern with two large forward-facing eyes
- Size: Body length ranges from 0.5 to 2 inches depending on the species
- Web: Does not spin webs to catch prey; uses silk only for retreats or egg sacs
Habitat
These spiders are found in many environments, including gardens, grasslands, forests, and even homes. They often hide under rocks, leaves, logs, or ground litter.
Behavior
Wolf Spiders actively hunt their prey rather than waiting in webs. They are solitary, ground-dwelling spiders and are most active at night. Females carry their egg sacs and even their spiderlings on their back.
Venom and Risk to Humans
Their venom is not harmful to humans. A bite may cause mild pain, itching, or swelling, but they typically flee rather than bite.
9. Zebra Jumping Spider (Salticus scenicus)
Named for its black-and-white striped pattern, the Zebra Jumping Spider is a common sight in California. It is small, curious, and known for its excellent vision and agile jumps.
Identification
- Color: Black with white stripes, giving it a zebra-like appearance
- Marking: Bold horizontal stripes on the body and legs
- Size: Small; typically 0.2 to 0.4 inches long
- Web: Does not build a web for catching prey; creates silk draglines and resting spots
Habitat
Zebra Jumping Spiders are often found on walls, fences, windowsills, and in gardens. They prefer sunny spots and are commonly seen during the day.
Behavior
These spiders actively hunt during the day and leap onto their prey with precision. They are curious and may even turn to observe nearby movement, including people.
Venom and Risk to Humans
Their venom is harmless to humans. Bites are extremely rare and, if they occur, cause only minor irritation.
10. Bold Jumping Spider (Phidippus audax)
The Bold Jumping Spider is a colorful, energetic spider commonly found across California. It’s known for its remarkable jumping ability and curious behavior.
Identification
- Color: Black body with white spots or stripes
- Marking: Iridescent green or blue chelicerae (fangs); white triangular spot on abdomen
- Size: About 0.4 to 0.6 inches long
- Web: Doesn’t spin a catching web; uses silk for draglines and shelters
Habitat
This spider can be found in fields, gardens, woodlands, and even inside homes. It prefers sunny, open areas and is often spotted on walls, fences, and tree trunks.
Behavior
Bold Jumping Spiders are active hunters during the day. They stalk and leap onto their prey using powerful back legs and excellent vision. They’re curious and often observe humans closely before jumping away.
Venom and Risk to Humans
These spiders are harmless to humans. Bites are rare and may cause mild redness or itching. They are more likely to jump away than bite.
11. Orb-Weaver Spider (Araneus spp.)
Orb-Weavers are famous for their large, intricate circular webs. They are common in gardens and yards throughout California and are completely harmless to humans.
Identification
- Color: Ranges from brown, orange, and yellow to reddish
- Marking: Fat, round abdomens often with patterns or blotches
- Size: Body length from 0.3 to 1 inch depending on species
- Web: Large, round, wheel-shaped web usually built at night
Habitat
Orb-Weavers thrive in gardens, forests, and around homes. They build their webs between branches, fences, or structures where flying insects are likely to pass.
Behavior
These spiders build new webs daily and often rest in the center or hide nearby. They are non-aggressive and prefer to flee if disturbed. They catch flying insects and help reduce pest populations.
Venom and Risk to Humans
Orb-Weaver bites are extremely rare and harmless. Their venom is not medically significant, and they are more helpful than harmful in home gardens.
12. Golden Silk Orb-Weaver (Trichonephila clavipes)
Also known as the Banana Spider, the Golden Silk Orb-Weaver is famous for its large size and golden-colored web. Though more common in the southeastern U.S., it has been occasionally spotted in Southern California.
Identification
- Color: Yellow-orange body with long black and yellow banded legs
- Marking: Elongated abdomen with white or yellow markings
- Size: Females can reach up to 2 inches in body length; males are much smaller
- Web: Large, golden-hued orb webs that can span several feet
Habitat
These spiders prefer warm, humid environments and are typically found in woodlands, gardens, and forests. In California, sightings are more likely in coastal or southern regions.
Behavior
Golden Silk Orb-Weavers are calm and non-aggressive. Females stay in their web, often suspended between trees or structures, while males roam in search of mates.
Venom and Risk to Humans
Though large and intimidating, their venom is mild and not harmful to humans. A bite may cause slight redness or irritation but is extremely rare.
13. Common House Spider (Parasteatoda tepidariorum)
True to its name, the Common House Spider is frequently found indoors throughout California. It’s harmless and often goes unnoticed as it helps reduce indoor pests.
Identification
- Color: Brown, tan, or yellowish with a mottled appearance
- Marking: Rounded abdomen with subtle patterns or speckling
- Size: Small; body length around 0.2 to 0.25 inches
- Web: Irregular cobwebs, often in corners or under furniture
Habitat
These spiders prefer indoor locations such as basements, garages, attics, and corners of ceilings. They may also be found in barns, sheds, or other human-made structures.
Behavior
Common House Spiders are non-aggressive and shy. They build sticky cobwebs to trap flying insects and often stay hidden during the day. They are more active when undisturbed.
Venom and Risk to Humans
Their venom is not dangerous to people. Bites are rare and typically harmless, causing little or no reaction.
14. Cellar Spider (Pholcus phalangioides)
Also known as “Daddy Long-Legs,” Cellar Spiders are commonly seen in homes across California. They are harmless and often confused with harvestmen, which are not true spiders.
Identification
- Color: Pale yellow, beige, or light gray
- Marking: Small oval-shaped body with extremely long, thin legs
- Size: Body around 0.25 inches; leg span can reach up to 2 inches
- Web: Loose, messy cobwebs, usually in ceiling corners or basements
Habitat
Cellar Spiders prefer dark, quiet indoor areas like basements, crawl spaces, ceilings, and closets. Outdoors, they may be found in sheds, garages, or under overhangs.
Behavior
They hang upside-down in their webs and may vibrate rapidly when disturbed. These spiders are not aggressive and feed on small insects and other spiders.
Venom and Risk to Humans
Urban legends claim they have deadly venom, but this is false. Their fangs are too small to penetrate human skin effectively, and their venom poses no risk to humans.
15. Lynx Spider (Oxyopes spp.)
Lynx Spiders are agile predators with excellent eyesight and spiny legs. While not commonly found indoors, they are active hunters in gardens and grasslands across California.
Identification
- Color: Green, brown, or tan with stripes or spots
- Marking: Spiny legs and long body; often blends into foliage
- Size: About 0.4 to 0.6 inches in body length
- Web: Does not spin a web for prey; may use silk for eggs or shelter
Habitat
These spiders are found in meadows, gardens, fields, and shrubs. They prefer sunny, vegetated areas where they can stalk and leap on insects.
Behavior
Lynx Spiders do not use webs to catch prey. They are active hunters and jump to capture insects. They can be territorial and are quick movers when threatened.
Venom and Risk to Humans
While they can bite if handled, their venom is not harmful to humans. A bite may cause mild irritation or swelling, but they are more beneficial than dangerous.
Summary:
California hosts a diverse range of spider species, from common harmless house spiders to a few venomous types like the Black Widow and Recluse spiders. These arachnids thrive in the state’s varied habitats, including deserts, forests, urban areas, and coastal regions. While most spiders pose little threat to humans, learning to identify the common species can help you coexist safely and appreciate their role in controlling pests.
