House lizards are not dangerous. They’re non-venomous, rarely bite, and pose no direct physical threat to people. The small geckos you see darting across your walls and ceilings are harmless in the traditional sense, but they do carry bacteria that can make you sick if you’re not careful about hygiene.
They’re Not Venomous or Poisonous
Common house geckos produce no venom and carry no toxins in their skin or body. There’s a widespread belief in many cultures that geckos contaminate food with poison, but this has been studied and debunked. Since house geckos are non-poisonous, food contamination from their mere presence isn’t a toxicity risk. If a gecko falls into your food, the concern isn’t venom. It’s bacteria.
Bites Are Rare and Minor
House lizards almost never bite people. They’re small, skittish, and their first instinct is to run. If one does bite (usually because it was grabbed or cornered), the bite is unlikely to break skin. These geckos have tiny jaws with minimal bite force.
In the rare case a bite punctures the skin, the main risk is a minor skin infection at the wound site, the same as any small animal scratch. A tooth fragment can occasionally break off in the wound. Cleaning the area with soap and water is usually all that’s needed.
The Real Risk: Salmonella and Other Bacteria
The actual health concern with house lizards isn’t their bite. It’s what they carry on their skin and in their droppings. All reptiles, including geckos, commonly carry Salmonella bacteria. They can harbor these germs even when they look perfectly healthy and clean.
Salmonella spreads through direct contact with a lizard or indirect contact with anything the lizard has touched: countertops, food prep surfaces, dishes, or floors where droppings have been. If you touch a contaminated surface and then touch your mouth, you can infect yourself. Salmonella causes diarrhea, fever, headache, and stomach cramps. In severe cases, it can lead to dangerous dehydration or blood poisoning.
Young children are at the highest risk because they’re more likely to put their hands or objects in their mouths without washing first. If children handle a lizard or touch surfaces where lizards have been, they should wash their hands with soap and warm water before touching their face or eating.
Gecko Droppings Need Prompt Cleanup
Gecko droppings are small, dark pellets often tipped with white (the white part is uric acid, their version of urine). You’ll find them along walls, behind furniture, on window sills, and near light fixtures. These droppings can contain Salmonella and other pathogens, and they’re the most common way house lizards spread germs indoors.
Clean droppings off surfaces with hot, soapy water. Pay special attention to kitchen counters, dining tables, and anywhere food is prepared or served. If lizards are active in your home, wiping down food prep surfaces before cooking is a simple habit that eliminates most of the risk. Avoid sweeping dry droppings, which can kick particles into the air. A damp cloth or paper towel works better.
Risks to Cats and Dogs
If you have cats, house lizards pose a specific concern that most people don’t know about. Cats that catch and eat geckos can pick up a parasite called the lizard poisoning fluke. Despite the dramatic name, “lizard poisoning” doesn’t mean the lizard itself is toxic. The danger comes from a fluke parasite that uses lizards and geckos as an intermediate host. When a cat eats an infected lizard, the parasites migrate to the cat’s bile ducts and liver.
Cats with a light fluke burden (fewer than about 125 worms) often show no symptoms at all. Heavier or longer infections can cause weight loss, poor coat quality, vomiting, jaundice, and diarrhea. Chronic cases can lead to liver fibrosis and liver failure. This parasite targets cats specifically. Dogs and other household pets are generally not at risk from it because the fluke’s life cycle requires a feline host to complete.
If your cat regularly hunts house lizards, it’s worth mentioning to your vet, especially if you notice unexplained weight loss or digestive issues.
They’re Actually Useful Roommates
House lizards earn their keep. A single gecko can eat up to 100 insects in one night, including mosquitoes, cockroaches, moths, ants, and spiders. They’re especially effective hunters around porch lights, lamps, and other artificial light sources, where roughly 70% of their successful catches happen. The bugs drawn to your lights at night are essentially a buffet for geckos.
For many households, especially in tropical and subtropical climates, the pest control benefit of having a few geckos around outweighs the nuisance. You get fewer mosquito bites and fewer cockroaches without any chemicals. The tradeoff is droppings to clean and the occasional surprise of a lizard darting across your ceiling at 2 a.m.
Keeping Your Home Safe With Lizards Around
You don’t necessarily need to remove house lizards to stay safe. A few basic habits handle the risk:
- Wash surfaces before food prep. Wipe down counters and tables with hot, soapy water, especially if you’ve seen lizard activity in the kitchen.
- Clean droppings regularly. Use a damp cloth and dispose of it. Wash your hands afterward.
- Keep food covered. Don’t leave dishes, fruit bowls, or pet food uncovered overnight when geckos are most active.
- Wash hands after contact. If you handle a gecko or clean an area where lizards frequent, soap and warm water for at least 20 seconds does the job.
- Watch young children. Kids who’ve touched lizards or surfaces lizards use should wash their hands before eating or touching their faces.
If you’d rather not share your home with geckos, sealing gaps around doors, windows, and pipes will reduce entry points. Turning off outdoor lights at night removes the insect buffet that draws them in. But for most people, a house gecko on the wall is a minor housekeeping issue, not a safety threat.