Most of the small animals that share a Thai home are a nuisance, not a danger: ants find any crumb, cockroaches come up the drains, geckos chirp on the ceiling, and termites quietly eat wood. A clean kitchen, sealed food, dry drains and a landlord who books pest control when needed keep almost all of them under control.
Thailand is warm and humid all year, so insects and small animals never get a winter break. Newcomers from colder countries often see more creatures indoors in their first month than in a year at home, and that is normal rather than a sign of a dirty building. This page is for renters and long-stay residents and covers the everyday pests. Scorpions, centipedes and other animals that can actually hurt you belong to our guide to dangerous animals in Thailand, and mosquitoes have their own page with 23 ways to avoid bites.
Household pests in Thailand at a glance
- Most common
- Ants, cockroaches, small house geckos
- Worth acting on quickly
- Termites (damage) and rats (health and wiring)
- Leave alone
- House geckos, which eat insects
- Who pays in a rental
- Whatever your lease says; ask before you sign
- Snake indoors
- Not a pest problem: in Bangkok call 199 (free removal)
- Someone swallowed insecticide
- Call 1669 and keep the product label
Ants: the first visitors in any Thai kitchen
Ants are the pest almost every resident meets. Tiny ants find sugar, fruit, pet food and dirty dishes within hours, and they walk in along cables, window frames and the gaps around pipes. In a high-rise condo they arrive just as easily as in a ground-floor house.
The fix is mostly about food. Keep sugar, biscuits, cereal and coffee in jars or boxes that close tightly, rinse plates before they wait in the sink, and wipe the counter at night. Many Thai households stand the legs of a food cabinet or pet bowl in small dishes of water, an old and effective trick that ants cannot cross. If a trail keeps coming back, follow it to the entry point and wipe it with soapy water, which removes the scent the ants follow.
Red weaver ants and fire ants live mostly outdoors, in trees and lawns. Their bite or sting hurts, so wear shoes in the garden and keep children away from the nests.
Cockroaches and the drains
Large brown cockroaches live in the city's drains and sewers and come up through floor drains, especially at night and after heavy rain. Smaller cockroaches breed inside kitchens, behind fridges and in cardboard boxes. Both are a sign that food, water or an open route is available.
- Close floor drains with a drain cover or a lid at night, especially in the bathroom and on the balcony.
- Take the rubbish out every day and keep the bin closed; our guide to rubbish and recycling in Thailand explains collection.
- Do not keep stacks of cardboard boxes or paper bags indoors.
- Fix dripping taps and dry the sink at night, because cockroaches need water more than food.
- Use bait stations or gel near the problem area rather than spraying the whole room.
One cockroach after a storm is normal. Several every night, or small ones in daylight, means they are breeding inside, and that is the point to tell the landlord or the condo's juristic office (the building management).
Geckos and tokays: the lodgers worth keeping
The small, pale house geckos that run across walls and ceilings are harmless to people and eat mosquitoes, moths and other insects. They leave small droppings, usually under a light or along a curtain rail, and that is the whole downside. Most Thai families treat them as part of the house.
The tokay is different in size. It is a much bigger gecko, grey-blue with orange spots, and its loud call (the "to-kay" that gives it its name) can wake you at night. A tokay can bite hard if someone grabs it, so do not handle one. Leave it, or ask the landlord or a local rescue team to move it. We could not confirm the tokay's current legal status under Thai wildlife law, so we do not say whether it is protected; do not catch, kill or sell one.
To keep geckos out of a bedroom, close gaps around doors and air-conditioner pipes. Killing them only gives the insects they would have eaten a free run.
Termites: small insects, expensive damage
Termites eat wood and anything made from it, including door frames, built-in cupboards, skirting boards, books and stored cardboard. They work out of sight, so the first sign is often a thin tube of mud running up a wall, small piles of what looks like sawdust, or a door frame that sounds hollow when tapped. After rain you may see swarms of winged termites around lights; they shed their wings and pair up to start new colonies.
In a rental, report termites at once and in writing. The damage belongs to the owner's property, and treating a building is the owner's job, not something to fix with a spray can. Taking photos before you report also protects your deposit when you move out; our guide to renting a condo or house covers the move-in inventory. If you own a house, a pest-control company will normally inspect it before it quotes a price.
Winged termites at the light are a clue, not an emergency. Switch off the light, sweep up the wings in the morning, and check door frames and cupboards in that room for mud tubes. If you find them, call the owner or a pest-control company.
Rats and mice: close the gaps
Rats are common in Thai cities, in drains, markets and gardens, and some climb into houses through roofs, drains and the holes cut for pipes. They chew wiring, spoil food and leave urine. The US Centers for Disease Control and Prevention (CDC) names rodents among the animals that carry leptospirosis, which spreads through contact with urine in water or soil; our page on leptospirosis and melioidosis explains the symptoms.
Rats also attract snakes. The Queen Saovabha Memorial Institute, Thailand's snakebite authority, advises keeping the area around a house free of clutter and overgrowth that shelters rats, because snakes follow them. If a snake does come in, read our page on what to do about a snake in your house.
Store food in closed containers, keep the rubbish sealed, and wear gloves when you clean up droppings. Do not leave rat poison where children or pets can reach it. In a rental, holes in walls and roofs are the owner's repair.
Damp-loving pests: silverfish, booklice and mold
Silverfish, booklice and some beetles live in damp cupboards, behind wardrobes and among stored papers and clothes. They are mostly a sign of humidity. Air out wardrobes, keep clothes dry before you put them away, and do not store paper or leather against a cold outside wall. Our page on mold and humidity at home covers dehumidifiers and air conditioners, which deal with the cause.
Pest control: what a service or contract covers
Many condo buildings and housing estates arrange pest control for common areas, and some include private units on request. Ask the juristic office before you call anyone yourself. A house owner usually books a company directly, either for one treatment or on a contract with regular visits.
Before you agree to a contract, ask the company to put these points in writing:
- Which pests are covered (ants, cockroaches, termites, rats), because termites are often a separate service.
- Which products will be used, and how long people, children and pets must stay out afterwards.
- How many visits are included, and whether a free re-treatment follows if the pests come back.
- The total price, the contract length and how to cancel.
Prices vary with the size of the property, the pest and the city, and we found no published price list we could rely on, so compare two or three written quotes. In a rental, check the lease or ask the landlord in writing who pays before you book a service.
Using insecticide sprays safely at home
Household sprays, coils, baits and gels are sold in every supermarket and convenience store. They are effective, but they are poisons. The US Environmental Protection Agency's citizen's guide to pest control makes the same basic points that apply in any country: read the whole label before use, use only the amount it says, and store the product in its original container out of children's reach.
- Choose bait stations and gels over sprays where you can; they put less chemical into the air.
- Never spray near food, plates, a baby's cot or a fish tank, and open windows afterwards.
- Do not mix products or pour them into drinking bottles.
- Keep the label. If someone swallows insecticide or feels unwell after spraying, call 1669 for an ambulance and show the label to the medical team. Our list of emergency numbers in Thailand has the others.
A mosquito coil in a closed bedroom is not harmless. Coils and plug-in vaporizers release insecticide into the air you breathe all night. Use them with ventilation, and prefer a net or screens for sleeping; dengue mosquitoes are covered in our guide to dengue fever in Thailand.
Frequently asked questions
Are house geckos in Thailand dangerous?
No. The small house geckos on walls and ceilings are harmless and eat insects, including mosquitoes. The larger tokay gecko can bite if someone handles it, so leave it alone and ask the landlord or a rescue team to move it if it bothers you.
Why do cockroaches come up the drain after rain?
Large cockroaches live in drains and sewers. Heavy rain floods their tunnels and pushes them up through floor drains in bathrooms and balconies. A drain cover at night, a dry bathroom floor and a closed rubbish bin stop most of them.
Who pays for pest control in a rented condo?
It depends on the lease. Building-wide treatment is usually arranged by the juristic office, and structural problems such as termites in fitted furniture are normally the owner's to fix. Ask the landlord in writing before you book a service yourself.
How do I know if a house has termites?
Look for thin mud tubes on walls and foundations, small piles of powdery debris under wooden fittings, door frames that sound hollow, and swarms of winged termites around lights after rain. A pest-control company can inspect the building before it quotes a price.
Sources
- US CDC – Thailand traveler view (leptospirosis notice) (checked October 2026)
- US CDC – About leptospirosis (animals that carry it) (checked October 2026)
- Queen Saovabha Memorial Institute, Thai Red Cross – Information about animal toxins (archived copy, January 2023) (checked October 2026)
- US Environmental Protection Agency – Citizen's Guide to Pest Control and Pesticide Safety (checked October 2026)