What is the best spider killer for basements?

Spiders can be a nuisance in basements, spinning webs in corners and dark spaces. While most basement spiders are harmless, no one wants to walk through spider webs or have spiders crawling around. Using a dedicated spider killer is the most effective way to get rid of basement spiders and keep them from coming back.

What types of spiders are found in basements?

Some of the most common spiders found in basements include:

• Cellar spiders – Cellar spiders are also known as daddy long legs spiders. They have long, spindly legs and small bodies. They build messy cobwebs in corners.
• Fishing spiders – Fishing spiders are large, brown spiders that tend to hang out near water sources like sinks, pipes, and drains in basements. They don’t spin webs and actively hunt for prey.
• House spiders – House spiders come in several common species that all look similar. They have bulbous bodies and spiny legs and weave sheet-like webs. House spiders are very adaptable and thrive indoors.
• Cobweb spiders – Cobweb spiders spin messy, tangled webs in undisturbed areas of basements. The webs can be nuisance but help catch other insects.

While these types of spiders are generally harmless, no one wants them creeping around the basement. Spider killers can get rid of current populations and residual activity.

Why you need a spider killer specifically for basements

Basements present some unique challenges when it comes to controlling spiders:

• Cool, damp environment – Basements tend to be cool, damp places that spiders love.
• Multiple hiding places – The nooks and crannies of a basement give spiders lots of places to hide and build webs.
• Difficult to reach spaces – Basement corners, ceilings, and clutter can be hard to access for cleaning webs and spraying.
• Entry points – Open windows or gaps around pipes and wiring give spiders way to get inside.

General pesticide sprays may not be strong enough to fully eliminate basement spiders. An indoor spider killer formulated specifically for basements can help:

• Strong enough to kill spiders where they hide
• Residual action keeps killing for weeks after application
• Can be applied in hard to reach cracks and crevices
• Prevents spiders from returning

How do spider killers work?

There are a few active ingredients used in the most effective spider killing products:

• Pyrethroids – Pyrethroid insecticides are synthetically created versions of pyrethrins, which come from chrysanthemum flowers. They attack the central nervous system of insects. Pyrethroids used in spider killers include deltamethrin, cyfluthrin, and bifenthrin.
• Neonicotinoids – Neonicotinoids are a new class of insecticides that act as neurotoxins. Imidacloprid and acetamiprid disrupt the nervous system of insects. They are very effective at low doses against spiders.
• Insect growth regulators – Growth regulators like hydroprene don’t necessarily kill spiders immediately. Instead, they interfere with an insect’s life cycle and ability to mature to adulthood and reproduce.

Spider killers combine some of these active ingredients for strong knockdown and residual effects. The ingredients work together to kill spiders on contact and prevent new generations from taking hold.

How to apply spider killer in a basement

When using any chemical pesticide, always take proper safety precautions and carefully follow label application instructions. Here are some tips for applying spider killer in a basement:

• Shake the container well before use to mix the ingredients.
• Target dark corners, along walls and ceilings, into cracks and crevices, under stairs and clutter.
• Spray 10-12 inches away from surfaces and structure to avoid oversaturation and drips.
• Treat entry points like windows, doors, and pipe openings.
• Apply directly to webs and nests for immediate knockdown.
• Reapply every 7-10 days for 2-3 treatments to break the life cycle.
• Ventilate the area well during and after application.
• Keep children and pets away during treatment and until completely dry.
• Always follow label directions for amount to apply and proper precautions.

Using a spray application allows the spider killer to penetrate hidden harborage areas where spiders lurk and breed. Reapplying keeps killing new generations as they hatch.

5 Best spider killers for basements

The following spider killers are specifically designed to eliminate spiders in basements and keep them away for good:

Product	Active Ingredients	Why It’s Effective
Raid Max Spider & Scorpion Killer	Imiprothrin, Cypermethrin	Strong pyrethroid formula delivers rapid knockdown and residual control. Kills on contact and keeps killing for up to 8 weeks.
Ortho Home Defense Max Spider & Scorpion Killer	Bifenthrin	Odorless, non-staining formula with powerful residual action for up to 12 weeks indoors.
EcoVenger Spider Killer Spray	d-Limonene, Pyrethrins	Natural active ingredients derived from citrus oils and chrysanthemums. Kills and repels spiders without strong chemical odor.
Spectracide Bug Stop Home Barrier Spider Killer	Lambda-cyhalothrin	Creates an invisible barrier that kills spiders on contact for up to 3 months. Also kills other crawling insects.
Terro Spider Killer Spray	Cyfluthrin, Imidacloprid	Kills spiders quickly and keeps killing for up to 8 weeks. Water-based formula won’t stain surfaces.

Key Considerations

When choosing a spider killer for your basement, look for these key features:

• Residual action – The longer a product keeps killing after you apply it, the better. Look for at least 4-8 weeks of residual activity.
• Multiple active ingredients – Formulas with two or more active ingredients tend to be more potent and effective than single ingredients.
• Method of application – Liquids and aerosols allow you to spray into cracks, crevices and corners where spiders hide.
• Odor – Some natural ingredients have strong smells. Synthetic ingredients tend to be low or no odor.
• Safety – Only use products designed for indoor use and follow all precautions.

DIY tips for controlling basement spiders

In addition to chemical sprays, there are some DIY techniques you can use to make your basement less inviting to spiders:

• Install weather sealing around windows and doors.
• Caulk cracks and crevices in the foundation.
• Keep clutter like boxes to a minimum.
• Reduce humidity with dehumidifiers.
• Improve ventilation with fans or open vents.
• Turn lights on at night to make the space less attractive.
• Vacuum webs, nests, and spiders regularly.
• Use sticky glue traps near common spider areas.

Keeping your basement clean, dry, and brightly lit gives spiders fewer places to thrive. Make sure to vacuum up any spiders you see to remove them before they multiply.

When to call an exterminator for basement spiders

While over-the-counter sprays can control basement spiders for most homeowners, it may be time to call for professional help if you notice:

• Large infestations of spiders or webs in multiple areas of the basement.
• Venomous spiders like black widows or brown recluses.
• Allergies or feared spider bites when cleaning webs.
• Spider problems that don’t improve after repeated self-treatment.
• Spiders keep appearing within days after removing webs.

Professional exterminators have commercial-grade insecticides that are stronger than what you can buy in a store. They also have the proper protective equipment and training to eliminate large or dangerous spider infestations.

Conclusion

Basement spiders are common but easily controlled with the right spider killer spray. Look for products with pyrethroid, neonicotinoid, or insect growth regulating ingredients that give strong knockdown and residual effects. Target corners, cracks, and entry points for best results. Reducing clutter and humidity also helps make basements less spider-friendly. Call a professional exterminator if you have a severe basement spider problem that over-the-counter remedies cannot resolve.