An 8-Step Guide to Eliminating & Preventing a Cockroach Infestation in Your Condo

Sure you saw something move out the corner of your eye? Felt something run over your leg in the night?

You may have cockroaches in your condo or house.

Now, I don't kill animals unnecessarily, but a cockroach invasion is a serious health hazard, especially when you have a baby in the house.

And that's the situation I was facing at the time: No matter how much I cleaned, how many I killed, they kept appearing — seemingly from nowhere.

Bear in mind that my apartment was fairly new, not more than 7 years old. So this problem doesn't just arise in older buildings, though undoubtedly the severity is likely to be greater in older buildings where roaches have had time to completely infest.

So rather than spending my life as a cockroach killer, I embarked on a mission to make my condo a natural cockroach repellent — a place where cockroaches didn't want to spend the night.

In this post I share my experience of expelling these pests from my condo and present my 7-step guide for you to do the same. This post will also come in handy for those viewing condos/houses for rent. If you know the telltale signs you can avoid moving into a roach-ridden property.

But first, a few things you should know about cockroaches in Thailand.

Cockroaches in Thailand

German cockroach and American cockroach are the two species most commonly found in Thailand. The German variety is the most likely to invade your condo, and the larger American type is the one you'll see scurrying out of a drain and across the street.

Knowing more about their habits can help you identify the most effective control methods.

Image Credit: Rentokil

6 Signs That You Have Cockroaches in Your Condo

1. Roach Poo – check for black grainy droppings in cabinets and along the floor where it meets the wall.
2. Smear marks – where water is present, you may see brown and irregular shaped smear marks on horizontal surfaces and wall floor junctions.
3. Shed skin – evidence of brownish skins can be found close to where roaches are breeding, as young cockroaches shed skins about 5-8 times as they mature to adulthood.
4. Egg casings – appear as small, dark brown oval-shaped casings (see the image in this post).
5. Unpleasant odour – you may detect a distinct musty smell when cockroaches are present in large numbers. Open cabinets and kitchen cupboards and have a sniff.
6. Getting sick regularly: If you have regular bouts of any symptoms in the graphic below, you may be getting infections from cockroaches in your home.

The 3 Most Common Associated Health Risks

Through their poop, urine, vomit and bodies, cockroaches transmit infectious pathogens. Around 32 different species of bacteria can be found on cockroaches, and they are responsible for spreading six different parasitic worms.

This means cockroaches are a serious health risk and can may you sick.

1. Asthma

Those who suffer from asthma are at serious risk. Asthma attacks may occur after inhaling allergens released by cockroaches. The World Health Organisation estimate around 23-60% of people with Asthma are sensitive to cockroach allergens.

2. Salmonella

Cockroaches are also known to spread salmonella. The Centre for Diseases Control (CDC) estimates that salmonella causes more than 1.2 million illnesses each year in the US, with 2,3000 of those resulting in hospitalisations.

3. E.Coli

Cockroaches can transmit E.Coli (Escherichia Coli), a serious food poisoning.

How Cockroaches Adapt to Your Routine

Most species of cockroaches are active (i.e. awake) during the four hours after lights-out. The cockroaches in Thailand are especially smart and quickly adapt to your routine. For example: when you go out to work, they may come out to play. But when you return and twist that door handle,  they scurry back into their crevices.

The most likely time for activity though is when you go to bed. They wait a while for absolute silence and then come out to feed and breed.

This is how cockroaches evade being caught and seen, and why you often don't discover that they live with you until it is too late. The first time you see one might well be by accident, for example when you open a box you haven't opened for a while, or you might see a dead one in a corner of a room when you move a piece of furniture.

If you want to do some cockroach hunting, lie in bed with the lights off for an hour and then switch on a light suddenly. Or quietly go to the kitchen and switch on the light. Move around some things on shelves and the worktop and you'll no doubt see one scurry.

Be Careful When Using Sprays

Sprays in Thailand can be very harmful to your health, especially if you are inhaling the chemicals regularly. Sprays are not a good long-term solution because you will be forever spraying and, when you miss, you'll panic and spray too much and end up poisoning yourself.

If you use a spray to kill a cockroach, get as close as you can and spray one solid spray in a direct hit. Then pick up and dispose. Never use sprays around babies, children or pets.

Besides, you need to treat the root of the problem, and for every one sprayed there's 10 more lurking close by.

Why Traps in Condos Aren't Very Effective

Man, I remember one time we went away for a few weeks and I put some traps down. Never again!

We retuned to find around a ton of dead cockroaches around the traps, but it quickly became evident that the traps had simply attracted all the other cockroaches in adjacent rooms to ours. And many hadn't fallen for the trap and instead taken up residence.

Why? Well, cockroaches attract each other, so if there's loads of others in close proximity they'll just wander in. Clearly some didn't take the bait. So not only was I left with a ton of dead bodies and a whole lot of poop to clean up, I had new friends too!

Prevention is better than cure.

Why Cockroach Infestations in Thailand Are Unique

Apartments/condos are in close proximity to other, so cockroaches can easily come into your apartment, feed, drink, lay and egg and then go to another room when disturbed. In this respect, it is unlikely that you will uncover one area in a room where there is a whole next of 20 or more. The most I found was 4 in one box.

This is different to a house infestation in Europe or the US, where growth is rapid and you will usually uncover a big nest with potentially hundreds.

What this means is that it is easy to be fooled into thinking the problem has gone once you have killed one or two. But if they have a reason to come back they will,

How Cockroaches Attract Each Other Using Poop!

You will usually see isolated instances of a single cockroach alone in the hallway of a condo block, but don't be fooled, these insects are geniuses at finding each other.

Cockroaches can communicate using their feces. Researchers studying roach aggregation behaviors found that compounds produced by bacteria in the gut of roaches help them find each other. The findings, published in Proceedings of the National Academy of Sciences, suggest that microbial communities in the gut enable communication.

So in short, you need to clean up their poo. Otherwise more and more will pay you a visit. The poo are like black breadcrumbs. The best way to identify it is to take a baby wipe and run it across a surface, like your kitchen worktop. Do this each morning to see whether there has been activity during the night.

Some poop I photographed on a kitchen worktop at an office building in Bangkok

An 8-Step Guide to Eliminating Cockroaches From Your Condo

Step 1: Cover Your Drains

The first, and a super effective way to prevent cockroaches entering your home is to cover plug holes and drains.

Make a habit of putting the plug in the sink after use. The same goes for the kitchen sink and the drain in your shower.

Also cover the drain in your balcony, as outside of the rainy season water flow will be minimal and roaches can easily climb up the pipe.

In addition, tape over your overflow hole in the kitchen and bathroom sinks. Cockroaches in Thailand live in the drains and pipes. They can move between rooms this way too. If you cover up you will cut them off and they'll go elsewhere.

Step 2: Cover Your Plug Sockets

The best advice I got on how to get rid of cockroaches was from an ex pest control guy. I met him by chance at a coffee shop and he happened to mention he'd worked in the game.

I was telling him that I just couldn't fathom why every time I thought I'd eliminated the problem more would appear.

He explained that the problem wasn't me but the building. “Once they get in the walls, you've had it. The condo building needs to be emptied and treated”.

By ‘in the walls' he meant behind the walls: in lift shafts, behind plaster board, etc. The roaches can breed and hide there undisturbed and then run in and out of apartments through gaps and sockets as they please.

The problem is that a condo owner isn't likely to admit they have a problem. You'll always hear the same excuses: it's rainy season, clean your room, it's because you're cooking, put traps down, blah, blah, bah.

It just wouldn't be possible for them to move everyone out and treat the building for  3 weeks or more. And, in reality, most Thai residents accept cockroaches as part of city living. So it's only you, “the farang”, who really complains.

Anyway. The guy advised me to cover all my unused plug sockets with tape, and keep the ones I used plugged in. I use extension plugs with surge master trips so it was safe to leave sockets plugged in. This one single piece of advice cut my problem by 60 percent or more. 

I noticed an instant reduction in the amount of cockroaches I saw in a week. But just because you can't see them, doesn't mean they aren't there.

Step 3: Leave Gaps Between Furniture

Having found tons of the critters over time, I deduced that they love to hide between a gap; so between a wall and a cupboard, behind a drawer, between crevices and papers.

To combat this, I pulled all furniture away from the wall by a good couple of inches. Not only does this mean you can keep a constant check with a quick peak here and there, but the Cockroaches won't feel secure resting in these places during the day and will vacate to a more suitable environment, i.e. outside of your condo!

Similarly, don't keep piles of papers in drawers. Throw old magazines away and regularly rustle, move and dust off  books to disturb the environment. Cockroaches love rooms with areas that remain disturbed. So do everything you can to upset the environment.

Step 4: Block Gaps Under the Front & Back Doors

Condo or house, I'm willing to bet a huge part of your problem is your neighbours. Unclean kitchens, strong smells and cockroach poo all attract other cockroaches.

So if your neighbours have roaches, the likelihood is you will get visitors too.

In a condo you'll find that roaches travel down the hallways at night, nipping in and out of the rooms. Much of this is done under the door. So reduce their ability to get in by blocking the gap under the door with a draft excluder or towel. It's not foolproof but it does help. Do the same with the back door.

Step 5: Empty Bins Daily & Wipe Surfaces with Disinfectant

If you have a smelly bin and your neighbour doesn't, the cockroach will show a preference for your lace. Empty bins daily and never leave strong smelling waste hanging about for long. Certainly never leave a dirty bin in over night.

Also wipe down kitchen, bathroom and any other surfaces on a daily basis. Cockroaches don't like disinfectant, and most importantly it is the only thing capable of effectively wiping up their poop, urine and vomit, which can attract other cockroaches.

Step 6: Keep a Minimal Home

This is massive, and really changed the game for me. In a nutshell, don't have too many things. Cockroaches love cluttered homes because they have so many places to hide.

De-clutter your home and throw out what you don't need. It makes it easier for you to clean, easier to spot roaches because they will be exposed, and help towards ending the infestation.

One thing I learned on my quest is that cockroaches love boxes. Cardboard boxes like shoe boxes are a great place for them to nest and rest.

They will hide there in the day and then venture out when you sleep. At one of the many points I thought I was winning the fight, I cleaned out the top of our wardrobe and got a box down with some odds and ends in. Man, what a shock! Three adult cockroaches chilling out among the bits and bobs.

Make sure you clean regularly and disturb everything

Step 7: Hunt for Eggs!

Most people have no idea what a cockroach egg looks like, or how the sneaky buggers deposit them in your home.

Each egg contains an outer sticky substance that can be stuck to the most obscure of places. See the image below.

This image is from an egg I found when cleaning out a sideboard. At the last moment I thought, let me check the underside of one of the structural panels. Strategically placed underneath was a cockroach egg waiting to hatch. These creatures are smart. They know when to roam, where to hide and where to lay eggs to evade capture.

So when I say you need to clean out your entire condo or house, I mean strip it bare and leave no stone unturned. 

Close up of the same egg

Step 8: Inform & Educate Your Neighbours 

I'll be frank: You probably won't get much co-operation from your neighbours. You might if they are interested in cleanliness and good hygiene, but I found that most young Thais and the Chinese residents in my building didn't seem that bothered.

And this was the key problem. Had we worked together it would have been more effective. But if people are frying food every day and not cleaning surfaces and pans, and not emptying bins regularly, this is a recipe for disaster.

You might try putting a sign with a list of dos and don'ts for others to follow, and posting a copy under each door. The more cooperation you have, particularly on your floor, the more likely you are to eliminate the problem.

——–

I did get rid of my cockroach problem but it took me about month to do. And they did come back a few times after, but I acted quickly and, knowing from experience where they liked to hide, I was able to upset their plans.

However, I did move out in the end. I was just too paranoid about them coming back and having my child at a health risk. Moreover, the building management would not admit they had a problem which really annoyed me after a while.

It sucks though, especially when you like a place and an area and this problem persists to the point where you have to up sticks and move. Hopefully though my tips will help you tackle the problem.