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!

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!
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!
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!

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!

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!

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.
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.

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!
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”.

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!

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.

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.

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!

 

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.
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.
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!

 

Conclusion:

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:

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.

 

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?