Sandflies on Koh Chang

Sandflies on Koh Chang

It’s not only Mosquitoes that Bite

I receive quite a few emails from visitors to Koh Chang who worry about catching Malaria here.  In reality, that’s not going to happen.  Or statistically the chances of getting it are so small that if you’re worried about that then you might as well put a bet on Elvis being alive and living in Bangkok, as there’s more chance of that happening.

Dengue fever is far more common, not just on Koh Chang, but across south-east Asia.  If you’re going to worry about any mozzie borne virus then that’s the one that should concern you. However, there are numerous ways that the potential for a life threatening mosquito bite can be mitigated.  Resorts will all ‘fog’ their grounds weekly to kill them off.  There are numerous tried and tested mozzie sprays and repellents available at any pharmacy. And, wearing suitable clothing , especially in the evening is recommended in all guide books. 

And yet you still see people covered in bites.  Bites that itch like hell and easily become infected. And many people will assume, that despite taking all the precautions,  they’ve somehow been bitten by a large family of mosquitoes, when in fact they haven’t.  It was sandflies. And they are common on Koh Chang and the nearby islands of Koh Mak and Koh Kood.

What are Sandflies?

Sandflies are tiny insects, only a couple of millimeters in length. They live in various habitats.  But the one’s we’re concerned with are those that enjoy life on quiet beaches in Thailand.

In Thai, sandflies are called ‘Pung’ or ‘Lin Talay’. The sandflies in Thailand are black with either black or white wings. The ones with white wings usually cause more allergic reaction.

As they are so small and make no noise they aren’t easily noticeable.  Which is why people often wonder why they have bites when they didn’t see or hear any, far larger, mosquitoes. In general, you can find sandflies on beaches at any time of the year. 

Why Do Sandflies Bite?

Sandflies are similar to mosquitoes in that females need blood from mammals, reptiles or birds to make their eggs. When female sandflies bite, they inject saliva that contains allergens which trigger the body’s immune system and cause an allergic reaction.  


Not everyone is affected the same way. A family can go to the beach and when they return to their hotel they find that one of them is covered in itchy, red spots but the others are fine or have very few.  In the worst case, symptoms include skin irritation, persistent itching, red bumps and swelling. If you see people with legs or back that looks like they have measles then it’ll be spots from sandfly bites.  

( Personally, I notice when they bite me.  I feel a small prick and a little itching for a few minutes but that’s all.  It’s annoying, but only briefly.)

Symptoms don’t always show up immediately.  It can take a few hours.  You could be bitten repeatedly in the afternoon and not notice until you are out for dinner. When it starts, you will feel itchy and become aware of the red bumps.

The severity of the symptoms vary from person to person, depending on your immune system. For those who are not overly allergic to sandfly bites, the bumps will disappear by themselves after 3-5 days, as long as you don’t scratch. Scratching intensifies the itching and aggravates the skin irritation. Meaning, it often takes longer to heal and you may end up with scars. So, don’t scratch however much you might want to.

How To Cure Sandfly Bites

Although the bites can be extremely itchy , the golden rule is to avoid scratching.  A hot shower can also reduce the itching.  However this is only temporary.  So, as soon as you notice bites, the best course of action is to head to the nearest pharmacy. 

There are many certainties in life, such as death and taxes, but also that any pharmacy near any beach will have seen hundreds of people with the same bites as you.  So no need to worry about not speaking Thai or not knowing what medication you require.  The pharmacist will give you an antihistamine cream loaded with steroids.  It’ll be far stronger than the stuff you can buy without a prescription in at home. And, as such, far more effective. Use that and the itching will stop very quickly.  The only downside is that it isn’t going to prevent you getting more bites. 

There are other home remedies for relieving the itching.  People have tried pretty much everything from Tiger balm to toothpaste with varying degrees of success. 

How To Prevent Sandfly Bites

Prevention is better than cure. But with sandflies it isn’t so easy.

Firstly, the obvious clothing tip. Wear light-coloured, loose-fitting, long clothing (cotton and linen) as much as possible.  Which is fine in the evening but not practical all day.   Also, a lesser known tip that actually works is to avoid using sweet smelling, scented soaps, shampoos, deodorants and perfumes. Bugs are attracted by the sweet smells.  Use odourless equivalents if possible.

Staying in a built up area also works.  You won’t find any complaints from people being bitten on the beach in Pattaya. Stay in a busy area with lots of people walking on the beach daily or at a resort where the sand is raked daily.  Sandflies lay their eggs in the sand. If there are a lot of people on the beach, these eggs will be destroyed and there will be no sandflies.  Likewise if resorts rake the beach daily. 

So there’s less chance of being badly bitten if you stay on a popular beach full of large resorts such as White Sand beach on Koh Chang.  And far more chance on any beach on Koh Mak which is famed for it’s long, peaceful stretches of sand.

The more lonely and natural the beach is, the more chance of finding sandflies. However, sandflies are more active early morning and late afternoon. So visiting a quiet beach, in the middle of the day will help.   In addition, they like cool, sheltered areas.  So if there’s bright sunshine and a sea breeze blowing you are less likely to encounter them.  The obvious downside is that it’s a bit mad to sit out in the burning sun in the middle of the day.  

If you think that you were bitten in your hotel room by sandflies, then there’s a good chance that you brought them back from the beach on your town or beach mat.  Always shake it off before you get back to your room.

Sandfly Repellents

Unfortunately, there’s not one repellent that is guaranteed to work and prevent you getting bitten.  If you get bitten or are in an area where you see other people with a lot of red bites on their legs and back then it’s worth asking what works , or what doesn’t.  But some to try include: 

– A mosquito repellent with a high concentration of DEET.  This has a good chance of working.  The downside is that it’s not particularly healthy for long term use.  80% DEET is strong enough to kill pretty much any known life form and will dissolve plastic. 

– Applying coconut oil on your skin.  A popular option.  Coconut oil is easy to find in shops. This makes your skin sticky and deters the sandflies – as they don’t want to get stuck to you.  The downside is that you’ll smell like a Pina Colada and will cook yourself in the sunshine.  Plus you have to regularly apply the oil.

– Apply a mix of Dettol and baby oil on your skin.  A mix of the stickiness plus household cleaner.  You’ll smell like a hospital ward but many people swear by this.

 – Take a Vitamin B tablet.  Apparently doing this longterm creates an odour in the body that sandflies and mosquitoes don’t like.  You’ll need to take it for a couple of weeks in advance of your holiday and whilst you are here for it to have any effect. 

– Citronella.  A fragrant, natural option.  You’ll smell lovely and won’t use any harmful chemicals.  Unfortunately, you’ll almost certainly still get bitten. 

Stay safe :-)



  • Thank you so much. That’s all you have to know about sandflies, perfect. No need searching for other information.

  • Another thing you can try is to use heat to kill the poison from the bites. This only works on fresh bits. Take a teaspoon, put it in boiling water and then press it onto the bite for a short time. I know a couple of people who do this and say it works well. Stops any itching very quickly and leaves no marks on the skin.

  • I wish I read your very useful advise before being bitten by sandflies.

    I did all you suggested, from going to the pharmacy to using coconut oil and smelling like pina colada. :)

    Let me add that put ice cubes over the blisters give you some relief.
    thank you for sharing !

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Koh Chang Island Guide For Independent Travellers