House Geckos: Why We Usually Leave Them Alone

New arrivals in Ho Chi Minh City find geckos on the walls and reasonably ask whether something should be done. They move suddenly, they appear at night, and they leave droppings on shelves and skirting.

Our usual answer is that the gecko is doing something useful and the droppings are the price. It is one of the few situations where the honest recommendation is to leave the animal alone.

What they eat

Common house geckos feed on mosquitoes, small moths, flies, ants, spiders and cockroach nymphs. A single gecko working a wall near a light consumes a meaningful number of insects over a night, and in a city with year-round mosquito pressure that is not a trivial contribution.

They also indicate something useful. Geckos concentrate where insects concentrate, so a wall with several geckos on it is telling you where the insects are, which is information rather than a problem.

They are harmless to people

House geckos do not bite people in any meaningful sense, carry no disease of significance in this context, and cause no structural damage. The complaints are aesthetic and about the droppings, which is fair enough but worth separating from a health concern.

Gecko droppings are also frequently mistaken for mouse droppings, which causes unnecessary worry. The distinguishing feature is a chalky white tip, which is uric acid, on a dark pellet. Mouse droppings are uniformly dark throughout.

What actually reduces them, without killing anything

Reduce the insects and the geckos follow, because they are there for the food. Change bright white outside lights to warm or yellow tones, which attract far fewer flying insects. Fit screens. Close the gap under the door.

Beyond that, sealing the gaps around the air-conditioner wall penetration and the trunking removes the routes into the room. Nothing on that list involves killing an animal and all of it also reduces the insects you did not want either.

When management is genuinely warranted

There are real cases. A food production or preparation area, where any animal in the space is a contamination and audit issue regardless of its diet. A hospital or laboratory environment. A large population in an electrical room or a server room, where geckos entering equipment causes faults and where an animal that dies inside a housing is a real problem.

In a home, the cases that justify intervention are usually a genuinely large population indicating a substantial insect problem underneath, or a specific location such as inside an air-conditioning unit where the animal cannot get out.

The air-conditioner case

Geckos enter indoor units through the wall penetration or the trunking, get into the fan housing and cannot reverse out. That produces a noise, sometimes a smell, and occasionally a fault.

This needs an air-conditioning engineer to open the unit rather than a pest technician, and the preventive measure is sealing the wall penetration and fitting a mesh cap on the condensate outlet — which is worth doing anyway for ants.

What we will not do

We do not use glue boards for geckos in domestic settings. They are indiscriminate, the animal dies slowly, and the outcome is worse than the problem. Where a gecko genuinely has to be removed from a sensitive area, exclusion and physical removal are the appropriate methods.

Where a customer specifically wants them gone from a home, we will say plainly that the effective approach is insect reduction and proofing rather than killing the geckos, because a wall that supports geckos will support new ones within weeks.

The tokay gecko, briefly

Larger, blue-grey with orange spots, and notable for a loud repeated call at night that surprises people who have not heard it before. It will bite if handled and the bite is painful, so it should be left alone rather than caught. It is also considerably less common inside apartments than the small house gecko, and it is generally a garden and older-building animal.

Related reading

See our house gecko guide and, for what they eat, our mosquito guide. The entry routes are covered in air-conditioning routes and physical proofing. For droppings, reading droppings. Our parent company covers commercial gecko control in Vietnamese through its house gecko control service.

Global Pest Control is the English-language arm of Khử Trùng Toàn Cầu, based in Thu Duc City.

Common questions

Are gecko droppings a health risk?

A very low one in a domestic setting, and they should still be cleaned off food preparation surfaces as you would any animal droppings. Reptiles can carry salmonella, so the sensible response is normal hygiene rather than alarm. In a commercial kitchen the calculation is different, because any animal presence is an audit finding regardless of risk.

One has been in my bedroom for a week. Should I remove it?

You can encourage it out by opening a window at night and turning off the room light while leaving a light on outside, which usually works within a night or two. Catching one by hand often results in a shed tail, which is harmless to the animal but distressing for everyone involved.

Do more geckos mean more insects?

Broadly yes, and that is the useful way to read them. A sudden increase in geckos in one room usually means something changed about the insect supply — a new light, a broken screen, a nearby breeding site. Following that question is more productive than counting geckos.