Spring Cleaning: Exterminating Tatami Bugs

Companion piece to “Spring Cleaning: Tatami-Bug Prevention.”

If you find yourself sporting the dani‘s tell-tale double bug bites, what should you do?

Take your futons to the Laundromat. Wash your clothes. Wash your pillow. Wash your carpets. Remember, heat kills dani, so if you can run the clean laundry and bedding through a drier, do so. Afterward, you can spray your bedding and clothes with Tomato Power or a clothing-friendly spray (see here) to prevent dani, but the spray will only repel them, not kill them. After your bedding dries, use your heated blanket to kill any remaining dani.

2. Clean, clean, clean!
Follow the instructions in the previous post and give your house a thorough cleaning.

3. Tell someone
You should tell your area leader, a friend, a trusted JTE, and/or your supervisor about what’s happening. They might have useful information, and you’ll need to talk to your supervisor if you need to get rid of old furniture, futons, or tatami in the process. Additionally, these people can help you talk to a pharmacist, recommend bug-bite creams, and help you pick out a bug bomb. (If your friends are really nice, they might even help you set it off!) Chances are that your acquaintances and coworkers who live in Japan have survived a dani infestation, too. You don’t have to suffer alone!

4. Use a bug bomb
If you are still getting bites after you’ve cleaned or you have more than just a few stray bites, you will probably want to use a bug bomb. How this works will depend on the layout of your apartment. If you have questions at any point in the process, see #3—talk to someone!

A smoke bomb for tatami bugs. Image from Earth Chemical Co., Ltd.

Bug bombs are not dangerous if used correctly. When people get sick or injured from using them, it’s typically because they used ones too big for a small room, used multiple bombs in the same room at the same time, stayed in the apartment during the bombing, or set off bombs multiple times in a short span of time. If you follow the instructions on the bomb, you should be just fine.

ダニアースレッド (dani aasu reddo) is one brand of bomb you can use. You pour water to the fill line to set off this smoke bomb. Similar bug bombs will have the phrase 水を使う (mizu wo tsukau uses water) on them.

First, get a dani-specific bomb of the appropriate size for your apartment/tatami rooms. The size of the area affected will be marked on the box (8-10畳 for 8-10 mats, etc.–the one in the picture is for 6-8 mats), so select one of the appropriate range. You should close off the tatami room(s) to set off this kind of bomb, but if you cannot close off the room, you will need to take extra precautions.

The instructions may be inside the container, so find them before you start.


  • Even if the room doesn’t connect to the kitchen, you should put away all of your food into the cabinets, the fridge, or in sealed plastic bags. Do not eat food that’s been sitting out after you set off a bomb. Don’t forget to move the spice rack into a cabinet
  • Get any pets or houseplants out of the apartment during the bombing. (For pets, you may want to wait a few days before bringing them back into the apartment.)
  • Close off the bathroom and shower rooms. You don’t want to get a tub full of bug-killing smoke or get insecticides in your makeup and shampoo.
  • If you cannot move clothes, luggage, toys, etc. into another closed-off room, put them in sealed plastic bags. You can also place these things in the closet, but if you plan to open the closet for bombing, take everything out first.
  • Plan to leave your apartment for two hours, come back, open all the windows and doors (within reason) and leave again for several hours. This is crucial. You cannot be in the apartment during the two hours after you set off the bomb, and you should only go back in to open the windows and clean up a bit before leaving again.

Preparations for immediately before you set off the bomb

You will have approximately 1-2 minutes to get out of the apartment after you set off the bomb, so you need to be sure to do ALL the preparations beforehand.

  • Move electronic devices to another room if possible. (Especially your laptop.) Cover your stationary electronics (wall AC/heater unit, TV, etc.) in plastic.
  • Cover furniture with sheets (wash these afterward) or plastic bags. (If you have a car or a friendly neighbor, you could store some items there, too.)
  • Cover your smoke alarm/carbon monoxide alarm with plastic wrap and secure with tape. The last thing you want is the neighbors getting angry or mistakenly calling the fire department while you’re exterminating.
  • Shut all the doors and windows.
  • Turn off the gas on your heaters.
  • Read the instructions on your package, or get a bilingual friend or coworker to help you. The instructions might be inside the package in the plastic wrap covering the bomb. Be sure you understand the specifics of the type of bomb you’ve purchased before setting it off.

Set off the bomb.
If you have all of your bags, lunch, etc., together, set the bomb off by removing the plastic wrapper around the smoke bomb, filling the container with water to the fill line, and placing the smoke bomb in the container. Shut the doors to the room as you exit, and get out. You only have 1-2 minutes before the smoke will fill the room, and you do not want to breathe in the insecticides.

The aftermath

After disappearing for about two hours, come back to your apartment and open as many of the windows/doors you as can to get air flowing. You can do some cleaning up, but you probably don’t want to linger.

  • Dispose of the bomb. Wrap in a plastic bag and place in the appropriate garbage bag for your community.
  • Wipe down all the windows and surfaces with a damp paper towel. Clean all food-preparation/eating surfaces, kitchen appliances, and exposed dishes with soap and water.
  • Vacuum the tatami. Throw out the vacuum bag afterward. Dani can live in the vacuum bag, too, so be sure to change it regularly.
  • Unwrap the plastic from the electronics and furniture. Dispose of the plastic or wash the sheets you used as coverings.
  • After you’ve cleaned to your satisfaction, leave the windows open and go somewhere else for a few hours.

The breeding cycle of dani is every two weeks, so if you have a bad infestation, you can bomb again in two weeks. Otherwise, wait and see, but clean more aggressively for a few weeks. Vacuum and wipe down your tatami every 1-2 days; change the vacuum bags frequently; air out your bedding whenever it’s warm and sunny; and use the electric blanket’s kill-setting every day.

If bug-bombing and cleaning fails to rid your apartment of the pests, talk to your supervisor about getting new bedding, new tatami, and/or calling in a professional.

Good luck and good riddance to dani!

Leah Zoller is a first-year CIR in Anamizu and really, really hates tatami bugs.

Additional Resources
Cornelia. April 2000. “Cleaning Problems Unique to Japan.” Japan with Kids.

Granberg, Paul. June 2004. “Bug Bomb Your House.” Tsukuba Alien Times.


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