Does Windex Kill Spiders and Their Eggs?

Spiders such as Black Widows and Brown Recluse use their venom to paralyze the prey, including humans, pets, and wild animals. We’ve discussed how you can repel or kill these arachnids using sprays, repellents, and spider bug bombs. Does Windex Kill Spiders

Windex is a standard and readily available household cleaner and stain remover. So, a spider has just appeared in your sitting or bedroom, and you’re wondering, does Windex kill spiders? 

The direct answer is, YES, Windex will kill spiders since it contains ammonia (in water – ammonium hydroxide) and sodium dodecylbenzene sulfonate that’ll block the spider’s book lungs (breathing holes in spiders) and thus suffocating it. 

Does Windex Kill Spiders and Their Eggs?

The ammonium concentration emits a gas that repels spiders (and other insects) from your house or compound. Windex can also kill other insects such as fruit flies, ants, and termites.

1. Ammonium hydroxide and Sodium dodecylbenzene sulfonate killing Spiders 

However, take caution when using it to kill stinging insects such as bumblebees, wasps, and beetles because you may get stung before killing. 

  • Their Killing action/ ingredients in Windex. The chemicals ammonium hydroxide and Sodium dodecylbenzene sulfonate found in Windex work collectively to kill the spider on contact. The Sodium dodecylbenzene sulfonate accumulates and clings on the spider’s air sacs blocking the path of air into the respiratory system, while Ammonium hydroxide is absorbed into the spiders’ bloodstream.
  • Oxygen is not absorbed into the bloodstream in the book lungs (during intake circulation) due to the high affinity of ammonia (ability to be absorbed by red blood cells instead of oxygen). Therefore, ammonia in the Windex will cause the spider to suffocate to death on inhalation.
  • Moreover, ammonium (ammonia dissolved in water) in the Windex product also acts as a repellant for spiders and other insects such as fruit flies found in your house or compound. The Compound emits unpleasant gas that keeps off spiders (ensure that you keep off the room when Windex is in action – it may chock you). 

Related: Spider Bite vs. Mosquito Bite

2. How to Use/Spray Windex for maximum action.

Windex product is the manufacture and packed in a liquid form. Its application is through spraying. Therefore, you will be required to follow these steps when using it.

  • Wear eye protection (goggles) and nose mask (protects the respiratory system) before use. The ammonium component in the Windex causes a burning sensation to eyes and irritation of the breathing system when inhaled (can even chock you).
  • Identify the spider hideouts (in holes, cracks, furniture, garage, within rocks, closets, or cobwebs) without disturbing them.
  • In case you are to use Windex within your house/room/enclosure, lock all windows and doors.
  • Then, remove the top protection seal.
  • Focus the Windex nozzle at the spiders’ hideouts before pressing of the trigger to commence spraying.
  • Spray rapidly at the spider infestation and leave the area before the spiders try to revenge/attack or escape.
  • You will also need to spray other places within the room (to saturation) to boost Windex’s killing power.
  • Lock the room for 30 to 60 minutes for the efficient working of Windex.
  • After the given period, open the windows and doors to allow fresh air to replace the choking ammonia within the room for 30 minutes.
  • In case you are using Windex in an open area (compound or fields), you will need to cover the spider’s hideouts with a bucket after spraying to prevent them from escaping before dying and also concentrate the killing power of Windex (wind may blow away spay before full action).

NB: Windex best kill spiders in enclosure/indoor. In case your spider infestation takes longer to die, I recommend you change to another spider killer in the market or use traps. 

3. How long (time) Does Windex Take to kill Spiders?

Windex kills on contact. It will take 1 to 15 minutes (maximum) to kill a single spider once the spray is inhaled. The following factors determine the rate and time for which the Windex kills a spider.

  • The concentration of ammonium content in a given Windex can. In case a can has a high concentration of ammonia, it will kill spiders instant-on contact, while lowly ammonia concentrated can take a little longer to kill spiders.
  • Typically, household Winder contains 0.05 to 0.1 (5% – 10%) concentration ammonia – this may not kill large spiders instantly on contact, but kills baby spiders and eggs perfectly well.
  • The Size of Area Being splayed. Large rooms (more than 200sq feet) need more than one can/bottle to ensure spider infestation is effective and wholly killed/eliminated. Ammonia in the Windex spray diffuses rapidly; thus, a given room should be saturated well when spraying to avoid the spider’s incomplete killing.
  • Type of Area being treated/sprayed. Windex spray kills spiders in an enclosed room faster than in open fields. Closed place/room concentrates the killing power of Windex while the open field loses the spray easily with the wind and has less killing effect on spiders. Windex spray directed to holes, cracks, and closet (spider hideouts) is more effective (takes less time) than one sprayed in the open space within a room or field/compound. 

4. What else Kills/eliminates spiders?

Apart from Windex, you can use the following substances or methods (natural/artificial) to kill or eliminate spiders in your place.

a. Use of Vinegar.

Vinegar is a weak acid of pH between 4 to 8 that emits a smell that keeps off spiders in your house or compound without necessarily killing them. You will require to mix 1 cup of vinegar with 5 cups of water. Then, spray the concoction in the spiders’ hideouts to saturation. You will need to spray the mixture twice per day for 10 to 15 days.

You can also blend white vinegar with coconut oil in a 5:1 ratio. The coconut oil will form a thick layer on their body, blocking their respiratory system. Also, the mixture emits an unbearable smell that keeps off spiders. You will have to spray this mixture daily for 2 to 6 weeks for the complete elimination of spiders in your home. This combination is friendly as it cause no adverse effect on the user on the application.

b. Using Black peppers.

Black peppers are a natural way of eliminating spider infestation in your home. It is a perfect solution when you need to repel spiders in your place than kill. You will need to grind several black peppers into fine pieces and sprinkle to spider hideouts.

You can also boil (3 to 4 cups of water) the black peppers and then strain the water before spraying in spider-infested areas. Black pepper is also able to repel other insects such as spider mites and ants.  Keep of kids while spraying your house/place – the spicy peppered liquid causes itching and burning sensation.

c. Use of Diatomaceous Earth.

Diatomaceous Earth is one of the best natural ways of killing and eliminating spiders and fleas in your home as it occurs as a natural siliceous and soft sedimentary rock that has a killing portion in it.

You will need to grind it into fine particles before sprinkling into spider-infested areas. Diatomaceous Earth acts on contact. It has sharp edges that penetrate easily, killing spiders’ entire life cycle (eggs, larvae, and adults). 

On contact, the Diatomaceous Earth absorbs fat and oil from the exoskeleton (specifical cuticle) of the spiders, thus killing them by dehydration.

Moreover, Diatomaceous Earth (for dogs) emits a smell that repels spiders and other insects such as cockroaches and fleas in your home. NB: Wear gloves (dehydrates hand), breathing Masks (causes irritation of breathing system), and use food-grade Diatomaceous Earth for safety measures.

d. Use of Essential Oils.

Essential Oils (like lavender) are natural spider repellents that help keep away spiders from your house or compound. They produce a smell that disrupts the spider infestation sending them off. 

Some of these Essential oils for bed bugs include Peppermint oil, pine oil, sweet orange oil, garlic oil, rose oil, cedarwood oil, and citronella oil.

You will only need to spray/apply essential oil in spider hideouts or infested areas every three days for a month. Essential oils also repel flies, lizards, and mosquitoes in your home.

5. Which other insects can Windex kill/eliminate?

Apart from eliminating spiders, Windex can kill other insects such as bumblebees, wasps, ants, spider mites, beetle, moths, and houseflies. You will only require to spray a colony of these insects, their path and hideouts, and you will find them death seconds.

Windex is quick-acting for regular household concentration when killing these insects. They are smaller and need less killing than spiders (you won’t need special concentration packages).

Windex will kill these insects by blocking the respiratory system (spiracles), thus suffocating. The cause of suffocation is insufficient supply/circulation of oxygen in the body, as ammonia remains held in red blood cells within hemocoel (open blood cavity in insects).

Moreover, Windex will repel these insects since the ammonium component in the product produces an odor that disturbs their presence.

Is Windex Poisonous to Humans and Pets When Used To Kill Spiders?

The Windex is not 100% for human use as it contains ingredients that affect both your humans and pets during use. Ammonium hydroxide may irritate the skin and respiratory system when inhaled. Also, it causes watery eyes and a burning sensation to your humans and pets on contact.

The fragrance and Liquitint sky blue dye used in Windex may cause respiratory disturbance and are a high source of allergy for allergic, sensitive people. These fragrances make your pets cough abnormally and even get choked.

Chemicals Hexoxyethanol, Isopropanolamine, and Sodium dodecylbenzene sulfonate cause skin irritation and burn on long use. They also have respiratory disturbance when inhaled.

NB: It is vital to wear eye protection, hand gloves, and a breathing mask when praying Windex.


Windex will kill spider infestation in your house or compound on contact. It contains an ammonium compound, which inhibits the absorption of oxygen in the book lungs of spiders, thus killing them by suffocation.

Sodium dodecylbenzene sulfonate in Windex blocks the chitin’s air sacs, making air impassable during the respiratory process. Windex also repel spiders and other insects such as bumblebees, wasps, ants, spider mites, beetle, moths, and houseflies.

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