How can you kill black widow spiders? Strong scents, vinegar, your vacuum cleaner, and pesticides are among ways you can get rid of this feared spider.
Black widow spiders, more venomous than a rattlesnake and considered one of the worst insects in the U.S., are found most often in basements, attics, and crawlspaces, and on the underside of furniture. Here’s why: Black widow spiders are fond of dark corners where spider webs will be left undisturbed.
Outside your home, black widows usually make their homes in woodpiles or in small holes in your yard.
Notorious for killing their mates, the term “black widow” encompasses 31 Latrodectus species that exhibit this ritual. Species of this shiny black and shy spider can be found everywhere in the United States and North America, but black widows are most common in warmer climates throughout the South.
Black widows, while known to have red hourglass markings on the abdomen, may have several colored dots or no markings at all.
With poor eyesight, black widows rarely leave their webs and rely on vibrations reaching them across their web to locate prey and other disturbances. Keep this in mind when confronted with black widows invading your space.
How to get rid of black widow spiders naturally
You can fend off or kill black widows just by using items you likely already have around your house.
Black widows are rumored to dislike lemon, eucalyptus, tea tree oil, and peppermint.
Why? Black widows smell through their feet, and apparently have a very good sense of smell. By dispersing these powerful scents, black widows will stay away.
How to make this spider repellent: Add your preferred essential oil to water to create a spray. Apply this to window ledges, baseboards, corners, and beneath furniture. Bonus: While a deterrent to spiders, your DIY spray doubles as an air freshener.
Note: Read the labels beforehand to be sure essential oils won’t cause any unintended harm to surfaces.
Vinegar is a black widow killer. Vinegar’s acidity will burn a spider’s body on contact.
How to make this spider repellent: Combine equal parts vinegar and water, and spray directly on the black widow. If you come across an egg sac, spray liberally on all sides.
Because spiders rely on their webs for both food and shelter, removing webs are your first defense in warding off black widow and other spiders.
How to use this spider repellent: Vacuum high and low to remove any spider webs; pay attention to hiding places such as corners and dark areas beneath furniture. Egg sacs should be targeted carefully, and then you’ll want to safely discard everything in the vacuum cleaner’s canister.
Note: Be mindful that the mother black widow rarely leaves her web, so she is likely to attack out of fear.
How to get rid of black widow spiders chemically
If homemade black widow killers aren’t doing the job, there are plenty of store-bought options to get rid of these pests.
Insecticides and pesticides
Chemical insecticides to kill black widows come in dusting or liquid options. Dusts are good for places humans won’t disturb, such as basements, crawl spaces, and window sills. Liquids are well suited to other areas, including known webs. Insecticides will kill any present spiders, and prevent new ones.
Oil-based pesticides including pyrethrin are best for targeting egg sacs. When you locate an egg sac, apply the pyrethrin liberally, coating all sides as possible. The pesticide will kill black widows and discourage others from moving into your home, garage or attic.
Since spiders eat other insects, removing flies, moths, grasshoppers, and earwigs will reduce spiders’ food source. Putting out traps for these pests will naturally reduce the likelihood that a black widow will choose to build her web nearby.
How to get rid of black widows inside your home
Black widows move into your house and take up residence in dark, often little used spaces such as the basement, attic, garage, crawlspace and shed.
- To make it easier to spot black widows, organize storage areas to force spiders to build webs in more visible locations, which are therefore easier to treat.
- To limit web-building opportunities, keep items in storage in tightly sealed containers (which also protect your belongings).
- To protect yourself on spider seek-and-destroy missions, wear gloves and protective clothing. Gardening gloves and close-toed shoes will keep your hands and feet safe. Wear denim or some other variety of work pants.
Once black widows are in your home’s dark and little-used areas, here’s how to evict these unwelcome houseguests:
Basements and attics
Apply a DIY chemical spray or a store-bought insecticide or pesticide wherever you have seen or fear black widows live in your basement or attic. Vacuum any webs you see.
Pro tip: After you’ve spotted signs of black widows by day, go downstairs (or upstairs to your attic) at night to apply your spider killers. Black widows are most active following sunset, so you’re more likely to have success.
Garages and Crawlspaces
Cold weather and drought drive spiders indoors, which is why you may see seasonal increases in black widows in garages and crawlspaces.
Apply black widow killers frequently and vacuum window frames, corners, and beneath furniture.
Pro tip: Sealing points of entry is the simplest way to keep spiders out. Install door sweeps, seal window openings, and repair screens. Look for openings at ground level that can be caulked or otherwise closed.
How to kill black widows outside your home
Discouraging black widows from moving onto your property is the best way to keep these arachnids outside your home. It also makes your backyard space safer and more enjoyable for whatever it is you like to do outside.
To deter black widows on your yard and property, take these four measures:
Remove web-building spots
Stacks of firewood are a favorite place for black widows to build webs, so get rid of these spider hiding places.
Tall grass also can be a web-building platform, so trim this grass regularly.
Secure tightly any garden bags and compost heaps. This eliminates a potential food source as well as a place to construct webs.
Limit outdoor lighting
Outside lights attract moths and flies, so keep the lights off to keep away a black widow’s food supply. Another option: Switch from incandescent to yellow or sodium vapor bulbs, as these are less attractive to flying insects.
Add birds and plants as deterrents
Wrens find black widows pretty tasty, so attracting these birds will help control the spider population. Install nest boxes and fill them with bread crumbs, peanut butter, or apple slices. However, keep in mind that feeding wildlife can cause other issues.
Add plants that black widows don’t like to beautify your outdoors and keep these arachnids away. Similar to the essential oils, pungent plants are disliked by spiders. Lemon balm, lavender, mint, and lemongrass are great options. Plant these pungent plants near garage, basement and house doors to help keep black widows from entering your buildings.
How to treat a black widow spider bite
Female black widows bite only in self-defense, and their bites are rarely fatal. They are not aggressive and will attack only out of fear. Black widows bite to protect themselves from perceived danger, which is sure to be the case if you’re caught disturbing her web.
What to do if a black widow bites you: Wash the area of the bite and apply an ice pack, the Mayo Clinic advises. Then seek medical treatment. Typically, black widow bites don’t hurt at first, but once symptoms set in, the neurotoxin can cause serious complications. Nausea, pain, and difficulty breathing will develop a few hours after the bite.
When to call a pest control expert
If you have a lot of black widows – or any spiders – in your home, call a pest control expert near you. Pest control professionals have specialized spider killers for attacking large and hard-to-reach infestations.
Main image credit: Black widow spider (Latrodectus macrons), the Western widow / Konrad Summers from Santa Clarita (Valencia), California / CC BY-SA