Spotting a spider is a terrifying experience, but spotting a black widow spider adds a whole new level of fear. Black widow spiders are infamous for their shiny black bodies and red hourglass marking on the underside of their abdomens. Their name comes from the widespread misbelief that female black widow spiders eat the male black widow spiders immediately after mating, although this rarely occurs in actuality.
However, they still deserve their scary name because the black widow spider bite is the most toxic spider bite in North America. Some sources even claim that black widow spider bites are 15 times stronger than a rattlesnake’s bite. Of course, you’re receiving far less venom from a spider bite than a rattlesnake bite, but black widow spider bites can still cause nausea, muscle aches, and make your breathing more difficult. Fatalities are uncommon, but the side effects of a black widow spider bite can be unpleasant and uncomfortable. Medical attention is strongly recommended if you’re bitten by a black widow spider.
In this guide on black widow spiders, we’ll cover the following topics:
- How To Get Rid of Black Widows Inside Your Home
- How To Keep Black Widows Out of Your Yard
- How To Identify Black Widows
- Signs & Causes of a Black Widow Infestation
Ed has been working in the pest control industry for years helping 1,000's of homeowners navigate the world of insect and rodent management. He manages Pest Strategies now helping homeowners around the world!
Table Of Contents
How To Get Rid of Black Widows Inside Your Home
So, you’ve found a black widow spider in your home. Unfortunately, finding one of these venomous spiders in your home likely means that you have many more nearby. A single female black widow spider can produce hundreds of offspring within a short period, leading to a massive infestation in your home.
Try the following steps to help get rid of black widow spiders in your home:
- Declutter your home. Black widow spiders love hiding out in cluttered areas of your home, such as the basement, piles of boxes, cluttered closets, attic, garage, storage area, and more. Take the time to carefully declutter these areas by getting rid of things you no longer need and cleaning up these areas so there aren’t food sources that may attract insects, which will attract black widow spiders. Ensure that you wear gloves, long sleeves, and pants during this process in case you come across any spiders while moving boxes.
- Examine your home’s exterior for cracks and crevices. Black widow spiders will find different entry points into your homes, such as open windows, holes in your door’s screen, and cracks in your home’s exterior. Do a thorough examination of your home for any gaps or holes that pests may be entering your home through. Then, replace any torn door or window screens and repair holes with a sealant or caulking product to prevent pests from entering.
- Dust your home thoroughly. If you notice spiders coming out of or hanging around electrical outlets or vent areas, use a duster to clean this area up. Then, replace the plate cover or vent cover to prevent spiders from using this to enter your home.
- Spray spiders with an aerosol spray. There are a variety of pest-killing aerosol sprays on the market that allow you to kill spiders and other pests with the spray directly. Keep a bottle of this on hand for any black widows you spot.
- Destroy spider webs. Web-building spiders, like the black widow, rely on their webs to catch their food. If you continually dust and destroy their spider webs with a broom, you prevent a spider from catching their next meal, which will eventually drive them out of their hiding places and out of your home.
- Make a DIY natural spider repellent. Like many pests, black widow spiders do not care for many essential oils, including peppermint, tea tree, eucalyptus, citronella, and lavender oil. To make a DIY repellent, add a couple of drops of one of these essential oils to a spray bottle filled with water and a few drops of dish soap, making the mixture stickier. Then apply this to common spider hiding places in your home, such as near baseboards, window sills, closets, garages, and more.
- Apply a spider insecticide. Purchase an insecticide treatment to kill spiders and apply this thoroughly to common spider areas in your home. Always make sure that you follow the instructions closely for any pesticide that you’re using and double-check that it can safely be used around pets or children if you have any around your home.
- Install door sweeps. Door sweeps prevent spiders and other pests from entering your home and can be excellent at helping with black widow spider control.
- Thoroughly clean your home. Get rid of black widow spiders in your home currently by cleaning your home with your vacuum cleaner. A vacuum cleaner can be an effective tool for sucking up egg sacs, spiders, insects, and food crumbs that may attract insects, the black widow’s food source, into your home. Once you’re done vacuuming, immediately empty the vacuum cleaner outside and take the trash off your property to prevent spiders from hatching on your property.
- Set out spider traps. Spider traps are usually glue boards that work by catching black widows on the sticky surface. Once captured, the spider cannot free themselves and can be disposed of easily.
How To Keep Black Widows Out of Your Yard
Spiders can be beneficial pests because they eat other more destructive pests, such as mosquitoes, beetles, and ants. However, if you find black widow spiders in your yard, we recommend immediately taking action because these venomous spiders may decide to eventually take shelter in your home, which presents a danger to you and your loved ones.
Here are our top tips for keeping black widows out of your yard:
- Eliminate other pest problems immediately. Black widows are web-building spiders that need insects nearby for their webs to catch. If you don’t have an insect problem in your yard, your chances of having a huge black widow problem are reduced. So, make sure that you immediately take care of any other insect problems in your yard, such as ants, mosquitoes, roaches, or caterpillars, which are all the preferred food sources of black widow spiders.
- Remove debris and firewood. Black spiders are notorious for building webs and hiding out in debris and piles of firewood. Remove these structures from your property. If you must keep them, move them farther away from the perimeter of your home to keep spiders from easily moving from the piles of firewood to your house. Make sure that you always wear gloves during this process.
- Apply a concentrate around the perimeter of your home. Purchase and apply a spider liquid residual concentrate around the foundation perimeter of your home. Take time to apply this carefully around your perimeter, including near window sills, door frames, vent openings, garages, deck areas, and more. This will make it difficult for spiders to breach your home.
- Maintain your yard regularly. Black widow spiders, along with many other pests, are attracted to overgrown yards, ledges, tall grass, and vegetation, which can provide them with easy access to your home. Make sure that you regularly mow your lawn and trim plants to keep this risk minimized.
- Change your light bulbs. Many insects are attracted to light bulbs. If you have lights, especially on a patio or deck, ensure that you only have them turned on when necessary. Also, consider changing the bulb to a sodium vapor or yellow bulb variety. These light bulbs are less attractive to insects, which will discourage insects from gathering near your home, reducing a black widow spider’s food sources near your home and in your yard.
- Attract natural predators to your yard. Birds, such as wrens, love to eat black widow spiders. Set up nest boxes and water foundations to attract birds into your yard, and they’ll eat away at your spider problem. However, keep in mind that this can backfire and cause a different wildlife pest problem.
A single female black widow spider can produce hundreds of offspring within a short period, leading to a massive infestation in your home.
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How To Identify Black Widows
Black widows are distinct spiders with all black bodies and red or orange markings on their abdomens. Female black widow spiders have the “typical” black widow look that we think of, with their all-black, shiny bodies and unique red hourglass shape on their abdomens. Male black widow spiders are notably smaller than their female counterparts. In addition, male black widow spiders don’t bite and are much less aggressive than females since they are not fiercely protecting their eggs. Male black widows will also have much longer legs that take up about half of their body proportionally, while female black widow spiders will have a more proportional appearance.
Both male and female adult black widow spiders have eight legs, eight eyes, a rounded body, and will range from three to 10 millimeters long, although females can sometimes be as large as 13 millimeters long.
Black widow egg sacs are spherical and white to gray in color. They typically contain one to two hundred cream or yellow eggs inside, which will eventually hatch into baby spiders. Most female black widow spiders will lay many egg sacs at once, so if you find one egg sac, you’re likely already heavily infested or on the brink of a spider infestation. Immediately call your local pest control professional if you find egg sacs because they will hatch shortly, allowing hundreds of black widow spiders to roam your property freely. Younger black widow spiders are white and orange but will turn black as they age. Like adult black widow spiders, they will have one or two reddish triangles on their body that may resemble an hourglass shape.
Like most web-building spiders, black widow spiders live on or near their webs, which they typically build in doorways, firewood piles, tall grass, and low to the ground. These locations allow them to easily access their preferred food sources, which are typically insects, such as ants, cockroaches, grasshoppers, and flies. As a whole, black widow spiders are solitary spiders and will live in dark, low activity areas near their messy, irregular webs. Typical areas that you may find black widow spiders include crevices in your home’s exterior, basement, closets, cluttered spaces, dark corners, garage, woodpiles, and more.
Signs & Causes of a Black Widow Infestation
Black widow spiders fall into the web-building spider category and, as such, are often in our homes building webs to round up their next meal.
If you suspect you have a spider infestation or black widow infestation, look for these signs:
- Webs in your home or outside on your property (black widow webs are typically irregular and messy and located close to the ground)
- Silken sacs, especially in doorways
- Noticing spider bites on your body
Causes of a black widow infestation:
- Cold weather (spiders seek shelter during unfavorable weather conditions)
- Drought (easy access to water inside)
- Easy access to food (insect infestations are likely to attract spiders and other pests)
- Unkempt yard
- Tall grass, debris, and firewood piles are great places for spiders to hide and build webs
- Other insect infestations
- Open windows
- Cracks in your home’s exterior
Black widow spiders are dangerous spiders that present a health hazard to homeowners and their families. Don’t hesitate to reach out to your local exterminator, especially if you find black widow egg sacs, which are a sure sign that you have an actual spider problem going on. While many other spiders, excluding the brown recluse spider, are benign pests that eat other more destructive pests in your home, black widow spiders are not a pest to mess with.
Do yourself a favor and immediately treat them or call a local pest control professional. Once the problem is dealt with, keep up with spider control and spider exclusion practices, such as regular lawn maintenance and decluttering to keep black widows away from your property in the future.