Finding spiders in your basement can be creepy and alarming. While most spiders found indoors are harmless, it’s understandable to want to get rid of them. There are several effective and safe ways to kill and prevent spiders in basements.
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Why Kill Spiders?
Many people are afraid of spiders or simply don’t want them living in their homes. Spider bites are rare, but some species like black widows and brown recluses can be dangerous. Webs can collect dust and look unsightly. Spider populations can quickly multiply and spread to other areas of the home. For these reasons, homeowners often want to eliminate basement spiders.
Common Basement Spiders
Some of the most common spiders found in basements include:
- Cellar spiders – Long, spindly spiders that make irregular webs in corners
- Cobweb spiders – Small spiders that build sheet-like webs in undisturbed areas
- Fishing spiders – Large, dark-colored spiders that don’t use webs to catch prey
- House spiders – Fast-moving spiders that hide in crevices and hunt at night
- Wolf spiders – Big, hairy spiders that live on the ground and chase down prey
While these spiders can look intimidating, most aren’t considered dangerous. Only the widow and recluse spiders have venom potent enough to cause serious harm to humans. Proper identification is recommended before killing any spider.
Chemical Spider Treatments
Pesticide sprays and dusts can be used to kill spiders and deter future infestations in basements. Products containing synthetic pyrethroids,deltamethrin, or lambda-cyhalothrin as active ingredients work well.
Spider Sprays
Liquid spider sprays are applied directly to webs, spider nests, cracks, and crevices where the pests hide and travel. The spray must contact the spider to be effective. Some popular sprays include:
- Raid Ant & Roach Killer
- Ortho Home Defense Max
- Spectracide Bug Stop Home Barrier
- Hot Shot Spider Killer
Follow all label precautions when using sprays. Cover exposed food, dishes, and surfaces before treating. Spiders hit with spray will die shortly after contact. Sprays help eliminate existing spiders. But web and nest remnants should be swept away and disposal of dead spiders is recommended.
Spider Dusts
Spider dusts contain powdered pesticides that adhere to the pests’ bodies as they crawl through treated areas. The active ingredients are then absorbed into the spider’s system, leading to death. Some dust options include:
- Delta Dust
- Drione Dust
- Borid Turbo Dust
- MotherEarth D Pest Control Dust
Dusts can be sprinkled into cracks, corners, along foundations, and other spots where spiders are active. The powder residue continues working to kill spiders for weeks or months after application. Reapply as needed based on product labels. Use a hand duster to efficiently apply dust in hard to reach areas.
Foggers and Bombs
Foggers and bug bombs release pesticide vapors that fill an entire room to kill hidden spiders. Close off the area being treated and leave for several hours after starting the fogger. Some options include:
- Raid Fumigator
- Hot Shot Fogger with Odor Neutralizer
- EcoSMART Organic Spider Fogger
- SpectracidePRO Fogger
Foggers work well for severe spider infestations. But they don’t provide any residual control after use. Any surviving spiders will need to be treated again. Foggers may also miss spiders that are hidden away in cracks or crevices.
Natural Spider Killers
For those wanting to avoid chemical pesticides, there are some natural spider extermination options:
Diatomaceous Earth
Diatomaceous earth (DE) is a powder made from crushed fossilized diatoms. The sharp particles abrade the waxy outer covering of insects and spiders. DE damages their body, causing dehydration and death within 48 hours of contact. Sprinkle DE in corners, along walls, and anywhere spiders are frequently spotted. Wear a dust mask when applying DE to avoid inhaling the fine particles. Food grade DE is safest to use indoors.
Essential Oils
Strong smelling essential oils like lavender, tea tree, peppermint, citrus oils, and eucalyptus oil deter and kill spiders. Mix 20-30 drops of oil per ounce of water in a spray bottle. Spray spider prone zones like windowsills, corners, vents and along the perimeter of your basement. The oils disrupt spider chemoreceptors making them unable to hunt prey or sense threats. Direct sprays will kill on contact and oils continue repelling spiders when dried.
Desiccant Dusts
Chalk, lime, kaolin clay, and other desiccant dusts abrade and absorb oils from spider’s exoskeletons. This leads to dehydration similar to diatomaceous earth. Apply a fine layer of dusts in spider hot spots. They will crawl through and get the particles stuck on their bodies. Vacuum up piles of dead spiders found after treatment. Desiccant dusts provide long-lasting spider control when left undisturbed.
Bug Zappers
Electric bug zappers attract flying insects but are ineffective against spiders. Zappers may actually increase the local spider population by providing them with an easy food source! Instead of a zapper, use sticky traps or pheromone based lures designed for spiders.
Sticky Traps
Place sticky traps wherever spiders are frequently spotted. The glue boards trap spiders that crawl across them. Once stuck, the pests are unable to free themselves and eventually die. For best results, use spider lures or attractants near the traps. Check traps periodically and replace when full. Sticky traps don’t kill as broadly as sprays or dusts but are useful for monitoring and controlling localized infestations.
Vacuuming
A simple vacuum with crevice tool is effective for removing spider webs and egg sacs. This helps eliminate food sources and breeding sites. Combine vacuuming with steam cleaning for the best results. The suction removes webs, bodies and eggs. Steam simultaneously kills live spiders and residual organic matter. Vacuum and steam baseboards, corners, walls and anywhere cobwebs accumulate.
Physical Spider Removal
For non-toxic spider control, physical removal is an option. This method requires diligence to clear webs and catch spiders by hand. It’s time consuming but avoids use of chemicals.
Spider Web Removal
Use a broom or vacuum to remove webs as soon as spotted. Knock down webs first then sweep up the debris. Pay special attention to corners, ceilings, fixtures, and undisturbed areas. Removing webs eliminates breeding sites and makes spotting live spiders easier. Without webs, spiders lose their trapping abilities making it harder to capture prey.
Catch and Release
Search the basement during daytime hours when spiders are inactive. Use thick gloves and a clear jar to catch and remove spiders. Place a thin piece of cardboard under the spider then scoop it into the jar. Cover it with a perforated lid, keeping the spider contained until you release it outdoors, away from the home. This technique works for larger, visible spiders but isn’t practical for removing all the hidden spiders from a basement.
Traps
Funnel shaped traps can be used to catch spiders wandering around your basement. Place traps along walls and in corners overnight. Check them in the morning and dump any captured spiders outdoors. Traps should have slick surfaces that spiders can’t climb up. Add some pesticide free bait such as raw meat or insects to attract more spiders into the traps.
Heat Treatment
Heating a basement to around 130°F and sustaining the temperature for several hours will kill all spider life stages. This involves bringing in special heating equipment aimed at cracks, voids, and clutter where spiders hide. The non-chemical treatment is effective but doesn’t provide any residual activity after the heat source is removed.
Preventative Measures
Along with directly eliminating existing spiders, take steps to make your basement less inviting to future spider infestations:
Sanitation
– Keep the basement clean and free of clutter like boxes, papers, and other items that create hiding spots for spiders.
– Sweep floors and vacuum carpets regularly to remove webs and spider “dust” accumulation.
– Clean counters, windowsills and other surfaces with soap and water to remove pheromones and organic matter that attract spiders.
– Fix any water leaks and moisture issues that draw in insects and spiders. Monitor humidity levels.
– Remove trash, debris and leaf litter from outside the foundation. Install door sweeps and screens to block spiders from entering.
Lighting
– Install bright lighting in the basement, especially along the perimeter. Spiders avoid well lit areas. Replace bulbs regularly.
– Use yellow bug bulbs that are less attractive to insects that spiders prey upon.
– Keep exterior lighting low or directed away from doors and windows. Outdoor lights draw flying insects and spiders inside.
Landscaping
– Trim back shrubs, trees and foliage touching the foundation. Vegetation can provide a highway for spiders to access your basement.
– Stack firewood and other items off the ground and away from the structure.
– Seal cracks and gaps around utility pipes that allow spiders to sneak inside.
– Replace mulch beds near the foundation with gravel, pebbles or decorative stone. Remove stone piles, dead logs and debris where spiders hide.
Sealing
– Caulk and seal any cracks, crevices or openings around windows, doors, pipes and the foundation. Use weather stripping around doors and door sweeps to block gaps beneath them.
– Repair damaged screens on basement windows. Add screen doors to exterior entryways.
– Install a steel wool barrier by packing steel wool into gaps then sealing with caulk. The fine metal strands block spiders but allow airflow.
Chemicals
– After removing existing spiders, apply residual insecticide sprays or dusts in the basement. Follow product labels and wear protective equipment when treating.
– Reapply chemical treatments every 2-8 weeks to keep killing newly emerging generations of spiders. Combine with non-chemical methods for best control.
| Spider Prevention Method | Steps |
|---|---|
| Sanitation | – Remove clutter – Vacuum/clean regularly – Fix moisture issues – Discard trash |
| Landscaping | – Trim vegetation – Clear debris – Replace mulch |
| Sealing | – Caulk cracks – Install weather stripping – Use door sweeps |
| Lighting | – Install bright basement lights – Use yellow bulbs – Reduce exterior lighting |
| Chemicals | – Apply residual sprays/dusts – Reapply every 2-8 weeks |
Conclusion
Preventing and eliminating basement spider infestations involves diligent monitoring and integrated pest management techniques. Start by vacuuming webs, removing clutter, and caulking gaps where the pests enter. Traps, natural oils or desiccant dusts provide lower risk control options compared to chemical sprays and foggers. For severe infestations, use pesticides labeled for indoor spiders according to label directions. Combining multiple methods and ongoing preventative steps will provide the best protection against basement spiders long-term. With persistence and patience, you can successfully banish these creepy crawlies from your basement once and for all!