I know that I have talked about this multiple times in the past but it is back in the forefront because I recently encountered them again. I've been down this road so many times that I don't even think very much about it and am not appalled when I encounter them. This doesn't mean that I will knowingly stay at a place that has them, but I'm just saying that as a budget traveler, this is an all but guaranteed part of your travels.
The more expensive places are no less likely to have them, they are just a lot more likely to do something about it when they discover them. As the business owner, this is a terrible situation to find yourself in because they are almost impossible to get rid of once they have taken hold, especially if you can't afford to close the business long enough to ensure that they are all dead. Just like any other insect, 2 become 4 becomes 8 because hundreds in a short amount of time. Their ability to survive chemical attacks is basically unparalleled and really the only thing that definitely works is really high temperatures.
That being said, as a traveler you can stay calm and keep your head level if you do encounter them, even if it is the day after once you discover they are there.
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I intentionally chose a silly kids game instead of images because they are kind of gross when you zoom all the way in on them. The problem with these guys is that if you pick 2 of them up, or a pregnant female - and the females are kept perpetually in that state, they replicate very quickly. They also do not need to feed for long periods of time and until they feed, they are almost invisible and very very small. It is only after they have already fed on you that you are probably even going to notice they are there at all.
You can still rest a little bit easy, because only about 40% of people react to their bites at all and they thankfully do not transmit any sort of disease. If they did transfer any bloodborne disease I think basically all of the tropical countries in the world would have long since been eliminated.
If you notice them where you are staying, do yourself and the business owner a favor and don't freak out and don't run to try to ruin their reputation online in one of your "Karen" moments. Chances are the business is either unaware that they are there are they are already doing everything that they have access to to prevent and eliminate them. Instead, have a quiet private conversation with someone in charge and just be cool. Chances are if you take a few precautions that they are not going to be coming with you to your next destination. One easy way to eliminate them is to find a place that has an electric dryer and crank that bad boy up to the top setting. Between the static electricity and the heat, this will kill them.
Other methods that work but take more time is to put all your belongings into a black trash bag, seal it, and put it in the sun. This can take all day but it will work - I speak from experience and many instances of this exact thing happening.
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There are various insecticide laundry detergents available on the market and they do work. The only problem is that in 20+ years of global travel, I have never seen these products available in the countries that have the worst bedbug problems. Funny how that works huh?
If you are the type of person that reacts to bedbug bites and one day you have a bunch of small bites all over you that are far too concentrated to have been mosquitos I urge you to once again calm yourself. These bite marks are likely not the fault of the place you just checked into since they take several days to rise on your skin. I think that trying to destroy someone's reputation online is just a dick move generally speaking when something is beyond their control, but it is even worse to accuse a place of something that they didn't even do.
You should do everything you can to prevent them little buggers from traveling if you do find them, for the sake of everyone involved. These pests are very good at traveling and will thrive in an environment even if the establishment regularly treats for insects.
Unfortunately this is just part and parcel of cheap travel in tropical countries and from the dozens and dozens of guesthouse owners I have talked to all over the world, they actually DO care and DO take many steps to treat and eliminate infestations. It just isn't something that you can simply spray some Raid around a room and the problem is sorted.
So if you do encounter them somewhere the first thing you should do is not freak out. They are not dangerous (thankfully) they are just kind of a nuisance. You can do a lot more for the owners and the world in general by just doing your part to help not spread them, and also pointing it out to the owners in a calm and private way helps them to better address the problem than you just putting a scathing 1-star Google review out into the ether.
Happy travels!