Lysol can kill a spider, but it’s slow, wasteful, and far from the best option. Spraying a spider directly with Lysol coats its breathing openings, gradually suffocating it over the course of several hours. You may need to use as much as half a can on a single spider to get the job done, making it one of the least efficient pest control methods available.
How Lysol Actually Kills Spiders
Spiders don’t have lungs like mammals. They breathe through small openings in their exoskeleton called spiracles. When you drench a spider in Lysol, the chemicals coat these airways and block airflow, essentially suffocating the spider. This isn’t an instant knockout. The spider will often still move, and it may scurry away to hide before the chemicals fully take effect. Death can take several hours.
Because Lysol wasn’t designed as a pesticide, it lacks the neurotoxic compounds found in actual insect sprays that cause rapid paralysis. You’re relying purely on physical suffocation, which is why it takes so much product and so much time. A coated spider will eventually die, but you may never find the body if it retreats into a crack or behind furniture first.
Why It’s Not Worth the Effort
The practical problems stack up quickly. Half a can of Lysol per spider is expensive and fills your room with chemical fumes that aren’t great for you, either. Lysol is a surface disinfectant, and overspraying it in enclosed spaces exposes you to respiratory irritants. If you have pets, the risk is more serious. About 8.3% of pet poison calls to the ASPCA involve household cleaning products, and exposure through inhalation can cause coughing, trouble breathing, and watery eyes in dogs and cats. Cats are especially vulnerable because they groom chemicals off their fur.
There’s also the obvious issue: Lysol does nothing to prevent more spiders from showing up. You’re solving a one-spider problem while creating a chemical mess in your home.
What Works Better for Killing a Spider
If you need to kill a spider right now, a shoe, a rolled-up magazine, or a vacuum cleaner will do the job in seconds with zero chemicals. A standard insect spray designed for crawling pests contains ingredients that attack the spider’s nervous system and work almost immediately, though these carry their own ventilation and pet safety concerns.
Sticky traps placed along baseboards and in corners are a low-effort option that catches spiders passively. They’re especially useful in basements, garages, and storage areas where spiders tend to travel along walls.
Keeping Spiders Out in the First Place
Spiders follow their food supply. If your home has flies, gnats, or other small insects, spiders will move in to hunt them. Reducing moisture, sealing food, and keeping outdoor lights off at night (which attract the insects spiders eat) will cut down on spider activity over time. Seal gaps around windows, doors, and utility pipes with caulk or weatherstripping to block entry points.
Peppermint oil has some genuine repellent effect. A 2018 study tested several natural products and found that peppermint oil strongly repelled two out of three spider species tested. Lemon oil, despite being widely marketed as a spider deterrent, showed no repellent effect in the same study. To use peppermint oil, mix about 15 drops into water in a spray bottle and apply it around windowsills, doorframes, and other entry points. You can also place reed diffusers with peppermint oil in problem areas, flipping the sticks every two to three days.
Regular cleaning helps, too. Removing webs as soon as they appear discourages spiders from settling in, since they invest significant energy in web construction and will often relocate if their webs keep disappearing.