The false widow spider is a spider of the genus Steatoda, a widely distributed European species, being Steatoda nobilis. This spider is dark brown or black, and 9-14mm long with pale, skull-like marks on the abdomen.
A study conducted by NUI Galway in October 2017 found that there were 5 verified cases of false widow bites in Britain and Ireland. In these cases, the effects were mild or moderate as opposed to black widow bites.
False widows are not usually aggressive, but bite when scared or cornered. They bite, which is painful, red, and swollen, but generally recover in 24 hrs. The species is quite common in urban areas and normally close to houses, sheds, and walls.
| Characteristic | Description |
| Scientific Name | Steatoda species, most commonly Steatoda grossa and Steatoda nobilis |
| Common Name | False Widow Spider |
| Size | Body length ranges from 6–14 mm; females larger than males. Overall appearance is bulbous and compact. |
| Color & Appearance | Brown to dark brown or purplish with lighter markings on the abdomen; glossy, rounded abdomen; similar in appearance to black widow but less vivid. |
| Legs | Moderately long, slender legs; often darker near the body and lighter towards tips; used for web navigation and prey capture. |
| Eyes | Eight small eyes arranged in two rows; poor vision; relies on vibrations in the web to detect prey. |
| Habitat | Commonly found in dark, sheltered areas such as sheds, garages, basements, and under rocks or debris; often near human dwellings. |
| Behavior | Nocturnal; constructs irregular cobwebs in corners and crevices; shy and non-aggressive, bites only when provoked. |
| Diet | Feeds on insects and other small arthropods trapped in its web; helps control pest populations. |
| Venom | Venom is mild; bites can cause localized pain, redness, and swelling but are rarely serious to humans. |
| Reproduction | Females lay eggs in silk sacs attached to the web; spiderlings hatch and disperse on their own. Females guard egg sacs until hatching. |
| Lifespan | Typically 1–2 years; females often live longer than males. |
| Geographic Range | Originally Mediterranean; now widespread in Europe, North America, and parts of Asia, thriving in temperate urban environments. |
| Adaptations | Ability to thrive in human-altered environments; silk webs provide protection and efficient prey capture; cryptic coloration aids in camouflage. |
| Predators | Birds, larger spiders, lizards, centipedes, and some parasitic wasps. |
| Activity Time | Primarily nocturnal; females remain mostly in webs, while males wander during mating season. |
| Prevention Tips |
Reduce clutter in sheds, garages, and basements. Seal cracks and gaps in walls and windows. Keep outdoor lights minimal to avoid attracting insects. Remove debris and stones where spiders may hide. |
| How to Get Rid of Them |
Gently remove spiders and relocate outdoors. Remove webs regularly. Use sticky traps in corners and crevices. Contact pest control for large or persistent infestations. |
What Does a False Widow Spider Look Like
Here are the three ways to identify a false widow spider:
- Size: The Adult false widow spider can be between 7 – 14 mm in size, and females tend to be larger than males. This measurement is body length only, does not include legs.
- Color: The color of this spider is creamy or pale on a dark abdomen. These markings usually appear in the shape of a skull or an hourglass to help researchers determine its identity in other locations.
- Notable Features: The distinctive traits are a shiny body, a big belly, and a long-legged, compact body. These characteristics distinguish it from a host of other ordinary house spiders.
What is the Life Cycle of the False Widow Spider
Here are the three methods of the lifecycle of the false widow spider:
- Egg Stage: Females produce silk egg sacs, which are usually concealed in thick web nests. The eggs numbered 40-100 within each of the sacs and are guarded till they emerge.
- Spiderlings: Eggs: There is a period of 2-4 weeks before the eggs hatch. The small children of the spider move out of the sac and go in search of their webs.
- Maturity: Spiderlings develop in several consecutive moults over months, and are at maturity when female spiders are 914mm and male spiders 710mm long.
Where Are False Widow Spiders Commonly Found?
Here is the habitats of false widow spider:
- Habitat: They like warm, sheltered places like sheds, garages, wall crevices, and attics, and construct irregular webs to hide and feel safe.
- Geographical Range: They are now found throughout the UK, much of Europe, and have found their range extending to North America, particularly coastal and mild climate urban areas.
How Do False Widow Spiders Behave
- Web Style: They produce disorganized, messy nets near the ground or in dark spaces to produce stern meshes where they can capture insects and avoid exposure.
- Feeding Habits: They trap insects, woodlice, and even other small spiders with their sticky webs, after which they inject venom to paralyze them and feed.
- Activity: During mating season, males abandon their webs to seek females, who stay put to defend their hiding place and guard their egg sacs.
How to Prevent False Widow Spider Encounters
Here is the eight steps to prevent false widow spider encounters:
- Seal Cracks and Gaps: Seal Cracks and Openings: Seal windows, doors, vents, and baseboards with caulk to prevent movement indoors through small gaps.
- Declutter Indoor Spaces: Clean out the attic, basement, and storage areas of dead weights to eliminate cozy places where they rest and propagate.
- Vacuum Regularly: Clean up the areas such as corners, along the ceiling, along the wall, and the garage to maintain its dry conditions and eliminate potential nesting places.
- Reduce Outdoor Lighting: Indoors, use little light or bulbs that repel insects, which are a source of prey for spiders.
- Trim Vegetation: Trim bushes and tree branches along walls and windows to eliminate some sheltered routes into the buildings.
- Inspect Outdoor Items: Check garden tools, boxes, firewood, and potted plants so as to make sure there are no spiders hiding in them.
- Install Window Screens: Cover the openings and block them off to the outside using fine mesh screens.
- Use Natural Repellents: To prevent them, spray vinegar or peppermint oil in likely hiding places.
If you’re seeing spiders, schedule a same-day inspection now!
Is the False Widow Spider Dangerous?
False widow spider bites are painful and characterized by redness and swelling in the region of biting. The reaction is typically mild and self-limiting. Less than 5 percent of the bites cause fever, dizziness, or nausea, resolving with minimal treatment. The majority of bites are comparable to a bee or wasp sting, and pain is limited to less than 24 hours in more than 90 percent of instances. Severe allergic reactions are very rare and affect less than 1 out of 100 individuals. Such cases require urgent medical care. Contact the doctor in case the swelling becomes extensive, the pain increases, or breathing becomes challenging. Early treatment secures a complication-free healing.
