Most home remedies shared online for killing lizards, like eggshells, garlic, or pepper sprays, don’t actually kill them. Many don’t even repel them reliably. A critical review of lizard repellent methods published in the Journal of Silk found that common home remedies “often prove to be ineffective, and the presence of lizards continues to be a persistent nuisance.” If you have lizards in your home and want them gone, understanding what actually works (and what’s just internet folklore) will save you time and frustration.
Why Most Home Remedies Don’t Work
The list of supposed lizard-killing home remedies is long: eggshells near doorways, garlic cloves, onion slices, Tabasco spray, coffee and tobacco balls, mothballs, and naphthalene. In practice, none of these reliably kill lizards, and most don’t even deter them for more than a few hours. Lizards are fast, alert animals with strong survival instincts. A gecko that routinely catches flying insects under a porch light is not going to be outsmarted by an eggshell.
Coffee-and-tobacco balls are one remedy that circulates frequently. The idea is that lizards ingest the mixture and die from nicotine poisoning. While tobacco is genuinely toxic to small animals, getting a lizard to eat a stationary ball of coffee grounds is unlikely. Lizards hunt live prey. They track movement, not smell, when deciding what to eat. The same problem applies to any poison-laced bait that doesn’t move.
Cold Temperatures Cause Paralysis, Not Death
Spraying a lizard with ice water or trapping it in a cold container is sometimes suggested as a way to kill it. Cold does immobilize lizards, but it rarely kills them. Reptiles are ectotherms, meaning their body temperature matches their surroundings. When temperatures drop below about 45°F (7°C), lizards lose the ability to move their limbs entirely and enter a state called cold shock, sometimes referred to as torpor.
Research from the University of Miami confirms that cold-shocked lizards are “pretty much helpless until the temperature rises above 45 degrees,” but they are not dead. Once they warm up, they recover and walk away. A lizard sprayed with ice water in your kitchen will go stiff for a few minutes, then revive as it warms to room temperature. Cold is useful for temporarily immobilizing a lizard so you can catch and relocate it, but it’s not a killing method.
What Can Actually Kill a Lizard
If you genuinely need to kill a lizard (rather than remove it), the options that work are blunt and unglamorous. Commercial glue traps designed for rodents or insects will catch lizards that walk across them. The lizard dies slowly from stress, dehydration, or starvation, which is neither instant nor humane. Flyswatters or similar tools can kill a small gecko on contact, but this requires you to be fast enough to strike an animal that can sprint across a wall in under a second.
Commercial pest control sprays containing certain chemicals can kill lizards, but these are pesticides, not home remedies. They also pose risks to children, pets, and the insects that lizards were eating for you. Mothballs (naphthalene) are toxic enough to kill small reptiles in an enclosed space, but they’re also toxic to humans and pets, and using them outside of sealed storage containers violates their product labeling in most countries.
Essential Oils as Repellents: Pet Risks
Peppermint oil, eucalyptus oil, and lemongrass oil are popular recommendations for repelling lizards. There’s limited evidence they work beyond the first day or two, since the scent dissipates quickly. More importantly, if you have cats or birds in your home, peppermint oil is genuinely dangerous. The American College of Veterinary Pharmacists lists peppermint oil as toxic to cats when ingested or even inhaled. Symptoms include vomiting, fatigue, and altered mental state, with a risk of liver failure. There is no established safe threshold for cats, meaning any exposure is a concern. Birds face similar risks.
If you’re set on trying essential oils as a deterrent, keep them away from areas where pets eat, sleep, or groom. But know that you’ll likely need to reapply daily, and the lizard may simply move to a different corner of your house.
Removing Lizards Without Killing Them
The most effective “home remedy” is a cup and a piece of cardboard. Place the cup over the lizard, slide the cardboard underneath, and carry it outside. This takes about 30 seconds and actually solves the problem. If the lizard is too fast to catch at room temperature, spraying it briefly with cold water from the refrigerator will slow it down enough to trap.
For longer-term results, focus on what’s drawing lizards inside. They follow their food source. A single house gecko can eat up to 100 insects per night, including cockroaches and mosquitoes. About 70% of their successful hunting happens around bright artificial light, where insects gather. Turning off unnecessary outdoor lights near doors and windows, sealing gaps around door frames, and reducing indoor insect populations with screens or basic pest control will make your home far less attractive to lizards than any spray or powder.
Why You Might Want to Keep Them
House geckos and small lizards are among the most effective natural pest controllers you can have. That single gecko eating 100 insects a night is doing more to control cockroaches and mosquitoes than most store-bought bug sprays. They don’t bite humans, don’t carry diseases in any meaningful way, and don’t damage property. The droppings they leave behind are the main nuisance, and even those are small and dry.
If your concern is a large population of lizards rather than a single unwelcome visitor, the issue is almost certainly an insect problem attracting them. Solving the bug problem solves the lizard problem. Sealing entry points, fixing window screens, and reducing standing water near your home will cut off the food chain that supports indoor lizards more effectively than any remedy you’ll find online.