Life in Japan

6 Dangerous or Annoying Insects (and Other Pests) in Japan

If you’re planning to come to Japan in summer, there’s something you should know about first.
The crazy heat and humidity coupled with bad insulation of houses is one thing, but that climate causes another problem!
It’s the perfect environment for all sorts of creepy critters and other pests to grow and spread!

grasshopper in Japan

First, let’s have a look at the insects: There are many insects that I personally don’t mind or find rather cute, especially those that are similar to the ones I’m used to from back home.
Actually there are even some really beautiful insects as well, such as butterflies or the red dragonfly.

However, the majority of them is disgusting. And not only that!
The main reason why I wrote this blog post is to warn you! Some of them are dangerous and many tourists don’t even know about it! Some can hurt you badly, others can kill you! smilie
Although chances are low that it will happen to you, I think it’s important you have at least a rough idea of what to expect.


1. Suzumebachi – The Killer Hornet:

Suzumebachi (スズメバチ、雀蜂、胡蜂) which consists of the words “suzume” (sparrow) and “hachi” (bee, hornet) is better known in Western countries as Japanese giant hornet (Vespa mandarinia japonica).
THIS is my personal nightmare! Of course I’m afraid of a few insects and animals, but only bees, wasps and hornets cause me to panic!
And I’m talking about the relatively tiny European ones.
Now, this one is HUGE! And not only that, it can kill you! I’m not kidding! smilie
Obviously somebody who is allergic to the venom of bees will die from it. Suzumebachi’s venom is just so much stronger which is why it also can kill people who aren’t allergic to them, even adults, if the dose is sufficient. A significant number of people die every year in Japan because of this little monster.

My Japanese co-workers keep telling me that one sting doesn’t kill you, but the second time will, because by that time your body will show an allergic reaction. I’m not sure if that’s really true, but Japanese people keep telling me that.

Here’s a video where you can see a suzumebachi from close up. It’s really a huge monster!
(Note: It’s already dead, otherwise it would be too dangerous and stupid to do what that guy did!)

As most insects it’s active in summer, but you’re most likely to run into it in September and October. That’s also when I found one sitting on my bedsheets. But generally they can be around from May to November.

If you get stung, wash the wound with clear water, then try to get the poison out by squeezing. Don’t suck it out!
You should use a cream that contains “histamine”. After these frist-aid steps, go to a hospital or – if in the mountains – to a nearby mountain hut and get an antidote!

Those hornets can be very aggressive. Avoid wearing black clothes. If you have a dark hair color, then wear a bright-colored cap. Don’t use perfume!

One of the many bee-like insects in Japan.

This is probably a so-called “black suzumebachi” (クロスズメバチ), but I’m not sure. It’s always better to assume you’re facing something dangerous than the other way round, right?

There are many similar bee-like insects and all of them are huge! Even horseflies look similar if they’re just passing by. My strategy is to just run away instead of confirming what it is. That’s also the only strategy that kept me from being stung. Staying calm didn’t help! smilie

While it’s not very common that they invade your house (unless you live next to trees or they decided to have their nest under your roof), they’re still very present especially in rural areas of Japan. When traveling, be careful!

Warning sign of suzumebachi in Yumebutai, Awaji Island

If there are a lot of them around, you’ll find signs like this.
They suggest that you don’t make any hectic moves and slowly get some distance between you and the hornet.
“If you stay calm, they are not scary insects at all!!” – Yeah, right .. not gonna stay around to test if that’s true or not!


2. Mukade – Centipede

You’ll find a huge variety of centipedes in Japan, but one of them is especially dangerous:
Mukade (ムカデ、百足) is another giant creature in Japan, yet correctly spoken it’s not an insect.
In summer, especially after rainy season you might find them in your house or in your bed. smilie
You are most likely to see them if you live in the countryside close to mountains. They are very territorial, so just kicking them out, won’t help.
They would come back. I heard that many people pour boiling water on them and then cut them into half.

The following video has a lot of interesting information about the mukade:

The problem with this critter is that it’s very aggressive and it can bite you.
People often describe the pain as 10 times stronger than that of a common bee sting. Also the swelling on your skin can be quite bad.
In summer it’s very common for them to be all around the place outside, especially at night. I had a very unpleasant experience in Kyoto a few days ago which I posted on Facebook.

A centipede in Japan

There are a lot of other types of centipedes as well. This photo was taken near Gifu Castle in August 2010.

You don’t have to go to a hospital if you were bitten by a mukade, but it will hurt a lot, so it’s good to know what to do.
Go to a drug store and get something like “ムヒアルファEX“. It will help to cool the skin and release the pain a little.
Unfortunately there’s not much you can do to prevent them from invading your apartment. Japanese people tend to use this powder that is spread around the house, but it can’t guarantee that they will stay away!


3. Huntsman Spider:

You can take a deep breath now. This fellow is not dangerous, but it might freak you out nevertheless.
I’m not afraid of spiders, but when I saw my first huntsman spider I freaked out!
Their legspan can reach up to 30 cm!
Actually those spiders are not native to Japan, but have been accidentally imported! smilie
They do not have webs, but hunt their prey, often by jumping on it from above. They’re also very fast. That’s why they’re called “huntsman”.

Huntsman spider in Japan

The one in the photo was sitting on the wall outside of my apartment and even had an egg sac below its body.
A female spider can get aggressive when somebody tries to attack their eggs. Usually they are harmless, but bite if you provoke them.
The venom is not harmful to a healthy adult and usually there’s no need to go to a hospital after being bitten.

You’ll most likely run into them during rainy season as they look for shelter.
As scary as this spider might look, it’s actually useful because it eats cockroaches … probably the NUMBER 1 PEST in summer.


4. Cockroaches:

If you’re going to live in Japan, you need to know that you will have issues with these disgusting little guys! They are everywhere in summer. It doesn’t matter how clean or new your apartment is, they will come and pay you a visit!
Don’t freak out! If you see one in your apartment, get rid of it. It doesn’t necessarily mean you have a nest or anything.
As this is such a huge issue in Japan, you can easily buy traps and poison for cheap in most supermarkets and drug stores.
Very common are the “Hoi Hoi sticky traps” and the poisonous traps. A normal insect spray often doesn’t work well, so the “Goki Jetto spray” is the way to go.

In Germany you’ll only see roaches in very dirty places, so I was so shocked when I saw my first cockroach here in Japan. As I never had seen one before I wasn’t even sure if it was one at first.


5. Cicadas:

When thinking about insects in Japan, cicadas were always the first to come to my mind.
If you watch an anime that takes place in summer, you’ll surely always hear a buzzing sound in the background. When I was younger I thought that was some kind of machine, but it’s actually the cicadas!

Japanese cicada

Cicadas are quite big and some find them disgusting. I’m not a big fan of them, but I also don’t mind them.
Most of the time their buzzing is considered as a natural noise in summer and people find it relaxing to hear, but in some parts (e.g. parks) they can get so loud that it really hurts your ears! We’re talking about up to 120 dB! Technically that’s loud enough to cause permanent hearing loss in humans!

Other than the noise they are usually totally harmless for humans.


6. Other Pests besides insects

The following animals aren’t necessarily something you will run into when in Japan. It greatly depends on where you live and most tourists won’t even know they exist here. Yet I thought it would be interesting for people who intend to move to the Japanese countryside.


6.1. Frogs:

If you live in the Japanese countryside right next to rice fields, then from about May to August you’ll suddenly have extremely loud, croaking neighbors. The frogs are harmless and are actually a sign that the rice fields are in good condition.

Amagaeru, cute tiny frogs in Japan

The most common one is the so-called “amagaeru” (アマガエル, Japanese tree frog). It’s very tiny and I find them actually quite cute.
During the daytime they stay in the rice paddies, but at night they become active, hop near lights to catch the insects there.
That’s why I find some of them around my front door when I come home from work at night.
They’re actually quite useful and not a pest – apart from their noisy croaking at night.


6.2. Geckos:

To me personally geckos are not a pest at all. They are usually outside my windows at night to catch all the insects.
I find them rather cute and wouldn’t freak out if one of them comes into my apartment.

Geckos in Japan

However, some of you might find them disgusting and you have to know that they are VERY common in summer, especially in the countryside.
I see them every night! smilie


6.3. Mice:

Personally I have no experience with mice. I found a dead mouse in one of my cockroach(!) traps in late November!
They’re invading houses or apartments every now and then.
It’s especially likely to happen in the countryside and in old Japanese houses.
When you go into a drug store or a supermarket, you’ll find a lot of mice traps. That alone shows that it’s quite an issue in Japan.
Did you ever have issues with mice?


6.4. The Poisonous Snake “Habu”:

Japan doesn’t have that many poisonous animals. One of the most dangerous (as in: causing a lot of deaths per year) is the earlier mentioned “suzumebachi”.
Another really dangerous one is a poisonous snake called “Habu” (波布, Trimeresurus flavoviridis).
As far as I know they can mainly be found in Okinawa and it’s very unlikely that you’ll run into one.
While the venom is extremely strong, fatality rate is only 3%. If you are bitten, get medical treatment immediately.
In most cases you won’t die from the poison, but permanent disability can be caused in some cases.


6.5. Bats:

What? Bats? Well, to be honest this is more like a personal story, but I thought it might be good to share it nevertheless. I doubt that anybody will EVER run into the same problem, though.
Yes, Japan has bats – like many other countries, including my home country.
Moving to a really rural area, I suddenly had many of them around. I didn’t mind.

Until the first somehow made it into my apartment. I got the shock of my life! It was flapping around in panic, dropping poo all over the place. smilie
I opened the windows and waved my arms until it finally found its way out.
At first I thought it was a coincidence, but a few days later I had the next bat in.
After many sleepless nights and a lot of bat poo, I finally found out that they came in through the kitchen hood.
When I opened it, lots of poo fell out. After cleaning it thoroughly I literally had a mountain of poo in there. So disgusting.

A metal grid outside (outer kitchen hood) finally solved the problem. Now, I only find some bat poo on my car sometimes. smilie
Bats sometimes live in attics of old Japanese houses, but they’ll find other places to stay like in my case.
I think it’s important to know about that, although it really doesn’t seem to be very common.
Usually they are very shy, but they CAN bite and they COULD have rabies, so be careful!



As you can see, being in Japan in summer can be a quite disgusting experience.
There are so many huge insects, but also many tiny flies and mosquitos. You’ll have mountains of dead insects in front of your door the next morning!

Especially for Japanese boys this is paradise, though. They buy huge nets to go insect hunting.
They’re particularly interested in all the big beetles. Japan has indeed a lot of them. There are also many insect museums all around Japan.
If you ever happen to visit Nagoya Castle, there is a nice exhibition of all sorts of insects in one of the floors:

Insects' exhibition in Nagoya Castle

I hope this blog post didn’t freak you out too much, but it is a fact that all these creepy critters are around and you should know about them.
I think it’s important to know which ones are dangerous and what to do when you encounter them – or how to get rid of them.
I couldn’t cover the topic in depth, but I hope I was able to give you a good overview.
And if you are actually fascinated by insects in Japan and want to see and read more about it, I can recommend this blog to you. smilie


There are so many creepy things out there, so let me know if you’ve ever run into something I didn’t mention here.
Please share your horror stories with us!
Were you ever bitten by a mukade or stung by a suzumebachi?

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  • We have 2 huntsman spiders in our house. I was first creeped out by it…but after a few days of seeing them in my bedroom (yes, they just wouldn’t budge) and the family room, I don’t mind them now. Just as long as they don’t jump on my face or something, then all is fine. LoL

  • I’m pretty sure mice/rats are a problem in most areas of the world.
    The government of Canada advises against using sticky traps for mice, though. They often end up defecating and such which makes the situation 10X worse. If you find a mouse in a sticky trap, you should kill it ASAP.
    Do they have those spring traps?

    • I don’t think that mice are actually SUCH a huge problem in Japan.
      I’ve not seen any spring traps. I don’t think many people use them here.
      The most common stuff you’ll find is poisoned food, I suppose.
      Sticky traps are also popular.

  • hi :-)
    I was wondering why you didn’t mention flying cockroroaches?
    It would be very disgusting for me if one of those landed on me ^^;;
    I hope you update the article. I enjoyed it very much.
    cheers :-)

    • I know that some people have seen them, but I never have. And I don’t want to.
      There are rumors that they only exist in certain regions of Japan, but I guess I’d need to ask an insect expert to find out the truth.
      Totally understand that they’re creepy. Roaches are so disgusting and if they can fly there’s just more drama. :(

  • Very informative post, thanks! No one really tells you about the bad points to visiting/living in Japan. I was wondering if all these insects are in Hokkaido as well? The winters are a lot cooler there and is quite similar to where I live in Canada, where there are (thankfully) no monstrous insects (there are hunstman spiders but they aren’t as big as the ones in Japan as far as I know.) I plan to live in Hokkaido for a few months but have bad arachnophobia and was wondering if I’m going to have a huge spider pay me a visit in my apartment or something :/

    • Hokkaido also gets insects, though less than in other parts of Japan.
      As I don’t live in Hokkaido, I’m not sure how likely it is that you’ll run into a huge spider. But even here in Western Japan it doesn’t happen THAT often.
      It also depends on the season. In the colder months, there won’t be any insects.
      I wouldn’t worry too much about it. ;)

  • Not sure how up to date this blog is, but I’ve lived in Japan for a little over 10 years and have not had any troubles with spiders…just the small jumping ones inside the house. Now the rainy season has ended, and when I opened my door this evening to do some shopping, this gigantic spider squeezed his way into my place. I live in an old house in the countryside of Saitama, so I’m used to seeing lots of insects/cockroaches/geckoes etc… but this was the first time to see such a big spider. After my search, I realized it was a huntsman spider, but I was terrified when I first saw him knocking on my door and entering without permission. I tried to move him back towards the door with a broom, but in a flash, he was in another corner of the utility room. Just gave up, but will be looking for him before I put my feet into my shoes tomorrow morning. thank you.

    • The tiny spiders are VERY common, the huge ones not so much. I haven’t come across them every single year, but occasionally I did.
      There are sprays that work on these huge spiders if you’re willing to use chemicals in your house.

      Hope he’s gone now. ;)

  • Hello. I am currently living in Hokkaido. I have not lived here long, and do not really have a bug problem (I think because I live in the North). But last week I went camping with some friends. It was dark outside, and I suddenly felt something big on my leg! It felt huge. I never felt an insect that big. I quickly swept it away, but not before I got bit. This happened on Saturday, and it is now Monday. The bite hurts a little, but not badly. And it is not that itchy either. But it is extremely, extremely red, with a black dot in the center. It is also very big, and it is swollen up. I have no idea what bit me. Should I just let it heal naturally, or do you recommend I do something about it? Are there any good creams that you know of? Thank you for the blog post, it was very informative.

    • I’m sorry to hear you got bitten.
      Are you sure it was a bite and not a sting?
      Did you eventually figure out what exactly it was?
      Actually there’s a great cream I always take with me when travelling. It helps with many things such as centipede bites, jellyfish, mites etc.
      It’s called “Muhi Alpha Ex” (ムヒアルファEX).

  • Good post, thanks. I’d never heard an inkling about this big bad bug summer crisis.
    This is the kind of information that helps me appreciate living in Portugal.
    Great weather, great food, good beaches… a minimum of bugs.

  • Hello,
    I’m glad I found your page!
    Japan has always been a country where I wanted to stay for a few years just for life experience.. But then, not too long ago, I stumbled upon this information about big spiders (huntsman spiders) in Japan. THINGS WE NEVER HEAR ABOUT! URGH! I am scared of small spiders, I can’t even imagine how I would react in front a of big one. The other bugs you’ve listed, I would say I’m mostly disgusted by it, so I think, I think, I can manage them. But the spiders… The regions I was planning to go to is either Fukuoka or Kagoshima. Do you know what’s the case of the spiders there? Also, I’ve read other people’s comment quickly, it seems that some people are rather lucky, some others not so much. Some people will see a spiders maybe once a year or even 2 years..?

    Well, for sure, my fear of spiders is something I have started to work on because I can definitely not miss out on life adventures just because of them, right? But, I’m glad I stumbled upon this very important information of Japan. At least, I’m prepared. Imagine if I were to go being all clueless and face it one morning.

    • Calm down. I haven’t seen these super huge spiders more than three times in seven years and I’ve always lived in the countryside. Of course, it will happen less if you live in a big city away from rice paddies and mountains. ;)

      In the south (Kyushu) it’s usually warmer, so you should expect more insects than in northern regions (such as Tohoku or Hokkaido).
      Yet, like you said, it really also depends on your luck. You might not run into anything for a very long time.
      And the spiders are really the ones you should worry about the least.

      It’s more likely you’ll run into other creepy crawlers. ;)

  • I really really like Japan but gosh darn I’m so affraid to go at anytime but winter haha! Im from Canada and where I live I get scared if I see a spider the size of your thumb; even if they are totally harmless. I really hate bugs and honestly, out of all the “dark sides” of Japan, insects are my biggest concern x_x

    • I know. It’s one of the downsides, but it’s not like you can’t deal with it.
      In winter you usually won’t have to bother. It’s really gross in summer, though, especially when you live in the countryside. ^^;

  • hi, i am heading to japan (tokyo, kyoto and osaka) this coming mid june to end june and i am most probably staying in apartments… being someone who is VERY VERY afraid of insects, would you mind letting me know the probability of seeing it outside and inside apartments?

    also, is there a way to make it cooler in the apartments since the temperature will be warm in june? from your experience, what is the range of temperature it will be like from mid june to end june?

    • Hello,

      it’s extremely hard to tell. It depends on too many factors (like how old the apartment is, if it’s in the first floor or the 40th floor, if you live in a big city or the countryside).
      Generally speaking it usually gets bad AFTER rainy season, so you should be fine. That being said just make sure to only open the doors and windows with the mosquito screen still shut.
      Most apartments (outside of Hokkaido) will definitely have an A/C, so use it if you can afford it. It will cool down the room.

      • hello, thank you for your reply! what about outside? like at parks/shrines/temples? also, how is the weather during mid June to end june generally like for most years? I went to check out the weather forecast of Japan in june and it is generally 25-27 degree celcius, but I just wanna know from someone who has been staying there for quite some time!

        I’m hoping it’s not too humid but I doubt so! coming from singapore myself, I know how humid is like so… haha.

        • It’s not yet so humid, but it is already quite hot in June. It’s always hard to predict how the weather will be. If we have an early rainy season, you might have a lot of rainy days. Hard to predict. The 25-27°C sound about right. It still cools down at night, but not too much.

          Of course you might run into insects outside, but if you stay in cities and don’t go into the deepest boonies, forests or mountains, I wouldn’t worry much about it, really! :)

  • hello!!!!!
    I used to live in super 田舎area(長野ね) though, i have many times to encounter 蜂 that is not also wasp. yah, it’s really dangerous one. But i often play with them when i was only a kid, i and my friend totally realise how dangerous they are, but we cannot stop it. If you stay Japan forever and you have a child, your child definitely becomes like me. 東京とかに住むならそんなことないと思うけどanyway super country side if you live in kind of this things alway happen.

    • It’s true that we have to struggle with insects a lot more in the countryside or in the mountains.
      I was surprised to see so many suzumebachi in Hokkaido last summer. Others were afraid of the bears, I was just running away from the hornets. *g*

  • Although I’m native Japanese, I’ve never been to 北海道。I know three prefectures at most…
    あなたは本当に面白いですね。本当に面白くて一通りの項読み上げちゃいました。I really want to know what made you love Japan??
    And forgive my broken English. I’m typical Japanese. I can read well but I cannot write and speak well. But I don’t want to go fancy language school…..

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