
Good News! Nature’s most unsettling house guest is getting stronger.
We’re getting deep into cockroach season here in Japan, where those nauseating little balls of disgust wake up and greet us in our homes with surprise visits. However, this year, there seems to have been an increase in people struggling more than usual to kill the beasts with sprays.
▼ “So, there was a freaking huge cockroach but I didn’t have a GokiJet. I spent three hours fighting it with other, weaker spray, but what do you think?”
https://twitter.com/am8_01/status/739885037567410177▼ “If you keep spraying until the cockroach stops moving, you’ll be the one dying from overkill.”
https://twitter.com/O9nishi21stst6/status/743733316419870720▼ “Cockroach VS Three Women: In the end Asuka killed it but it took an hour. It flew and we screamed. After flying, we kept spraying it until after it died. The spray made it jump and we thought it was alive and we screamed. We’re tired.”
https://twitter.com/asuka_0114/status/743401952646569986It was enough to cause NHK News Web to look into what was happening with Japan’s cockroaches. They first asked insecticide manufacturers who constantly investigate the effects of a variety of substances on pests in an effort to improve their products.
While everyone assured that their sprays are still effective, a disturbing trend has been seen with certain German cockroaches (Blattella germanica). In collected samples found around Tokyo it would seem these roaches have an increasing tolerance to the neurotoxin permethrin, which is the most widely used pesticide in the world.
Some German cockroaches were found to be up to 200 times stronger against permethrin than average ones. Since roach sprays are combinations of ingredients, they’ll still work but this might explain why some people have to continuously spray a roach before they die…aside from their own terror that is.
▼ Many online see this as the beginning of Terra Formars, a sci-fi series in which highly evolved roaches set out to slaughter humans on Mars.
And their tolerance is only going to better over time. As roach expert Hideaki Tsuji told NHK, the German cockroach’s fast generational turnover allows them to evolve quickly. Thanks to natural selection, stronger roaches will survive until conventional sprays become useless in the not too distant future.
Luckily, cockroaches so far haven’t been able to adapt to my own personal insecticide: a spare block of wood by my front door that I whack them with. But when they do, god help us all…
Source: NHK News Web via Hachima Kiko (Japanese)
Top Image: Amazon 1, 2
Video: YouTube/Epicblargman

Japan’s “strongest roach killer” is frighteningly effective… We mean FRIGHTENINGLY effective
Japan’s 5.3 million beautiful Hitachi Nemophila flowers are now in full bloom[Photos]
Here’s the best spot to take in a panoramic view at “the most beautiful Starbucks in the world”
These apartments are crazy-small even by Tokyo standards, and super-popular with young people
Studio Ghibli announces first new short anime film in 8 years, exclusive to Ghibli Park
Mr. Sato shares his own secret Ministop hack to help save the ailing convenience store
Japanese government creates new word for cruelly hot summer days
Immerse yourself in TeamLab Yoro Valley’s outdoor nighttime art exhibition in Chiba’s wilderness
Wisteria season starts early with blooming of Japan’s Great Wisteria in its beautiful garden
Autonomous beverage and snack car now testing in Chiba City
A spotlight on Japanese singles figure skating: Jumping into the 2026 Olympics【Pt. II】
Brand-new Pokémon manhole covers coming to help the recovery of a disaster-stricken part of Japan
Japan’s awesomely beautiful Alpen Route snow corridor is now open
Injuries on stairs in Tokyo highlight an overlooked design flaw
Move aside, convenience store egg sando – there’s a better version of the iconic sandwich in Japan
Japan’s popular bead bonsai kit is as beautiful as it is gruelling to make
Japan’s best conveyor belt sushi restaurant of seven years ago has now, finally, come to Tokyo
Final version of Sanrio: Beginning of Kawaii exhibition opens in Tokyo[Photos]
Japan has new rules for bicycle riders, and these 14 things could get you a fine or a court date
Japan reportedly adding Japanese language skill requirement to most common foreigner work visa
Pokémon and Ikea Japan cross over into each other’s worlds with collaboration events
Japan now has a special desk for people who work at home with a pet cat[Photos]
Famous Tokyo cherry blossom spot installs view-blocking screens to fight overcrowding[Video]
Uniqlo announces new T-shirts for One Piece, Naruto and more for manga publisher’s 100th birthday
Krispy Kreme releases Super Mario doughnuts in Japan for a limited time
Survey asks foreign tourists what bothered them in Japan, more than half gave same answer
Japan’s human washing machines will go on sale to general public, demos to be held in Tokyo
Starbucks Japan releases new drinkware and goods for Valentine’s Day
We deeply regret going into this tunnel on our walk in the mountains of Japan
Starbucks Japan releases new sakura goods and drinkware for cherry blossom season 2026
Studio Ghibli releases Kodama forest spirits from Princess Mononoke to light up your home
Japan’s newest Shinkansen has no seats…or passengers [Video]
Major Japanese hotel chain says reservations via overseas booking sites may not be valid
Put sesame oil in your coffee? Japanese maker says it’s the best way to start your day【Taste test】
No more using real katana for tourism activities, Japan’s National Police Agency says