How to Get Rid of Spiders

Learn how to kill spiders with spider spray and pesticides.

When spiders start to emerge indoors, many people want to know how to kill spiders. We will discuss using spider spray and pesticides to get rid of these pests. We'll also provide some tips on preventing spiders from entering your home in the first place.

Spider Control Steps

Sanitation: Reduce Favorable Spider Conditions

    Remove some infestation sources such as clutter in the yard and crawl spaces and any ground covers against the foundational walls. Any sanitation step to remove favorable conditions is the first step in spider control. Getting rid of other insects with a routine insecticide treatment should be considered since other insects are their food sources.

  • JT Eaton Webster Cobweb Duster Headis convenient to clean cobwebs and used as an applicator tool for insecticide dust. This head can be placed on any standard threaded pole found at your local home improvement store.

  • Web Out is a natural product that not only removes the spider webs but repels the spiders as well. It will last 5-6 months inside and 2‐3 months outside.

Key Takeaway

Remove yard clutter and debris near the house and cut back any vegetation against exterior walls.

Kill Spiders and Insects ‐ Insecticides

Insecticide Concentrates & Aerosols

  • Perimeter Spray Treatment - If spiders are coming indoors, hunting for their prey, spray a residual insecticide treatment such as Onslaught Fastcap Spider and Scorpion Insecticide around all entry points and the perimeter of your house. Spray anywhere they are webbing, on decks, under eaves, on porches, and other areas on the exterior of buildings.
  • Indoor Spray Treatment - Spray along baseboards, in corners, and under furniture. Use an insecticide aerosol like PT221L Aerosol with a crack and crevice tip to spray along baseboards, window and door frames, corners, pipes, and other areas where spiders may crawl. These aerosols are convenient to spray in areas where a water-based product can not reach.
  • We have a kit with Onslaught Fastcap Spider and Scorpion Insecticide and PT 221L Aerosol in one kit called the Residential Spider Kit. Use the Onslaught Fastcap outside (it may be sprayed inside as well), and the PT221L Aerosol with its crack and crevice tip is used to spray into hiding places where the liquid can not reach.

Suggested Insecticide Concentrates

  • Onslaught FastCap - Microencapsulated; fast-acting; may be used inside or outside.
  • Avesta CS - Micro-encapsulated; spray inside and outside. It adheres well to surface areas and is ideal for perimeter treatments around structures.
  • Residential Spider Kit Use the Demand CS Insecticide as a residual liquid spray on the outside. It has little to no odor and adheres very well to surfaces. Use the PT 211L Aerosol with its crack and crevice tip to cracks and crevices both inside and outside. Spray where spiders or spider webs have been found.
  • Cyper WSP - Wettable powder; may be used inside or outside.

Key Takeaway

Remove spider webs before applying the insecticide.

This will force the spiders to contact the treated surfaces as they attempt to rebuild their web.

Monitoring with Spider Traps

Trapper LTD Insect Glue Boards will catch spiders and monitor the population. The Monterey Spider Trap will catch spiders and serve as a monitoring tool.

General Spider Characteristics

Many species of spiders are common household pests in the United States. Spiders are considered beneficial pests because of their prey to other insects. Because spiders have eight legs, they are easy to separate from insects, which have only six legs. Another distinction between spiders and other pests is that spiders do not have wings or antennae. Spiders are arachnids.

Spider Bites and Venom

To kill their prey, all spiders use venom. Not all spiders are dangerous to humans. If Black Widow Spiders and Brown Recluse Spiders, Hobo Spiders, and European House Spiders are found, pest control treatment should be considered. These spiders do not create spider webs indoors. Although there is generally little danger resulting from spider bites from most spiders, it is advisable to consult a physician for spider bites.

Brown recluse with penny
Brown recluse with penny

Brown Recluse Spiders

The body is yellow to dark brown, with a body size of 1/3-1/2 inch long. Combined with the legs, it could be about 1 inch or longer in diameter. The dorsal has a dark brown violin-shaped marking, very distinctive. Their web is off-white to Gray. They can be found outside, under rocks, debris, woodpiles, etc. However, they are often found inside Brown Recluse spiders can be found in storage areas like closets, basements, bathrooms, bedrooms, attics, garages, and cellars. Sometimes they can be around above the ceiling ductwork or register. When inspecting for Brown Recluse spiders, use gloves and a flashlight. Brown Recluse likes to stay hidden. Their webs are off-white to gray colors, and they are not extensive. Many times people get bit by putting their hands or feet in something that has been in storage. You should always wear gloves when handling debris outside the home. The initial bite is not intense but poisonous.

Click here: Brown Recluse SpidersFor more information on black widow spiders.

Black Widow
Black Widow

Black Widow Spiders

The female has a shiny black, globular abdomen with two yellow or red markings in a triangle shape. It looks like an hourglass. Males are smaller, lighter in color, with light streaks on the abdomen. The web is irregular, many times found along exterior foundations on slabs, under stones and rocks, behind shrubs. They usually don't enter structures. They will bite if provoked. The bite feels like a sharp pain, like a needle puncture. After 15 minutes to an hour, there will be muscular cramps. Bites are rarely fatal, but you should seek medical attention.

Click here: Black Widow Spiders For more information on black widow spiders.

Location of Spiders
Location of Spiders

Location of Spiders

Some Spider populations are found in humid and moist locations like basements and crawl spaces. Other Spiders prefer dry and warm places. They can be found in upper corners of rooms and attics as well as sub-floor air-vents. Spiders prefer to hide in dark areas and in cracks as a retreat to construct material for their webs.

Spider web on house
Spider web on house

Spider Webs (Cobwebs)

Some species web over lamps in corners, attics, and basements. A spider made every "cobweb."

Suggested Aerosols

  • PT211L Aerosol - The PT 221L has a long residual and excellent knockdown; it is a good all-purpose spray with a low odor.
  • D-Force HPX Aerosol- With crack crevice tip- Last 4-8 weeks.
  • Stryker 54 Contact Spray - This pyrethrin aerosol spray is used for killing spiders on contact and flushing them out of hiding places.

Insecticide Dusts ‐ Additional Treatment

For a large spider problem, use an insecticide dust like Cimexa Dust, D-Fense Dust in the attic areas. Other areas that can be dusted include wall voids and under baseboards with hand dusters

We also carry a Cobweb Duster Head to be placed on a standard pole. The brush head will hold the dust in place; brush it in places where the spiders make their webs. Place insecticide dust on the head and reach the corners in the basement, garage, and porch areas.

  • For large areas, use Dustin Mizer Duster. Dustin Mizer cranks out a lot of dust for excellent coverage in attics.

Written by our resident pest control expert Ken Martin.