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Why Do I See More Roaches After Bombing?

Why Do I See More Roaches After Bombing?

If you used bug bombs to eliminate roaches from your home, you might wonder, “why do I see more roaches after the bombing?”

Cockroaches grow into large populations in less time. Though bug bombs kill them effectively, there could be several reasons more roaches are coming out.

Read on to find out if it is okay or if you need to change your pest control strategy.


Some reasons you see roaches after the bombing:

  • Cockroaches get anxious and leave their hiding due to insecticide.
  • Manufacturers’ guidelines for bombing are not followed properly.
  • Bombing particles have not reached all the cracks and crevices.
  • Drawers and cabinets were left closed, making the bugs residing there safe.
  • Cockroaches’ eggs remain unharmed; they hatched and might have re-developed the colony.
  • Improperly closed foggers rendered the bombs ineffective.

While it is normal to see cockroaches around for some days after the bombing, it might also be alarming. Roaches are continuously developing resistance against commonly used insecticides.

In this article, you will find out why there are more roaches after the bombing. Moreover, we will discuss what you can do to eliminate roaches from your home. Let’s dig in!

Why Are There More Roaches After Bombing?

More Roaches After Bombing

The roaches you see around after the bombing don’t come out of the blue. They have been in your house all along. When you use insecticide bombs, the roaches don’t die instantly. Instead, the fly roaches take the poison to their nest and spread it among the fellows.

This poison makes them sluggish and anxious, leaving their nest searching for new places. You might find more roaches after the bombing, but it means that the bombs are working right. The roach population will decline in a few days.

The treatment takes some time to work properly, but there could be other reasons you see more roaches after the bombing. Here are a few:

  • Cockroaches are developing resistance against the insecticides used in bug bombs. Thus, the treatment might be ineffective against them, resulting in more roaches appearing. To counter this, you can pair bug bombs with other pest control solutions, like cockroach traps or extermination.
  • Bug bombs diffuse pesticide in the air, killing the roaches present around. But, it does not reach hidden corners and cracks where most roaches reside. The effectiveness of bombs against hidden cockroaches is pretty low.
  • You might not have opened all the drawers, cabinets, and shelves before the bombing. The roaches present there could come out after the bombing.
  • Using the right amount of bug bombs and following the usage guidelines are an absolute must with foggers. If you use lesser than recommended, there’s a high chance all the roaches won’t die.
  • The area where you use bombs must be completely closed for a few hours for the pesticide to set in and perform its action. If your home is not closed correctly, it will result in roaches coming out even after treatment.
  • Insecticides do not affect unhatched cockroach eggs. If eggs are recently hatched, you will see many more insects.

What To Do if You See More Roaches After Bombing?

More Roaches After Bombing

Bombing is an easy and effective way to get rid of roaches, but it is not foolproof. It is pretty common to spot nasty insects even after a bombing. So, what can you do to kill all cockroaches effectively?

We suggest giving bombing another shot with some extra efforts to prevent the reoccurrence of the roaches.

1. Follow the Product Instructions Properly

Follow The Product Instructions Properly

Bug bombs or foggers have different instructions and guidelines based on the manufacturer. Read and follow all the guidelines mentioned for a better result. Clean your home first and remove all the roach corpses from the last bombing.

Make sure to open all the cabinets and drawers. Clear your countertops of appliances, decor items, or anything the roaches can hide behind.

Also, detonate bombs near cracks, furniture, appliances, and pipes to eliminate the hidden cockroaches.

2. Use the Right Amount

Use The Right Amount

Getting stingy with the bombing will do no good if you intend to eliminate the roach infestation. Use enough bombs or foggers to cover your entire house, including the hidden spots.

Usually, bug bombs describe how much area they are suitable for. So, make sure you are using at least recommended per room. If the roach population is abnormally high, double the amount of bombs.

Also, use bombs near the hidden residence of the roaches.

3. Keep Your Home Clean

Keep Your Home Clean

It might sound like a no-brainer, but cleaning is essential to prevent roaches from taking over your home. It is your armor and shield against the attacking force of cockroaches.

Sweep thoroughly after the treatment to ensure no roach eggs are lying around to hatch and avenge their ancestors. Vacuum and clean your home surfaces frequently.

Keep your bin lid-covered and empty it regularly to prevent cockroaches from living around them. Do not leave food items outside; store them in airtight containers.

Moreover, never leave dishes unwashed. They invite cockroaches and other insects more than anything can.

Most cockroaches can’t stay long without water. So, dry and clean damp areas, such as near air conditioner units, water pipes, basements, and kitchen counters.

4. Give It Time

Foggers Or Bug Bombs

Foggers or bug bombs don’t work instantly. When you diffuse a bomb, the insecticide gets into the air. It settles onto the surfaces, killing roaches that come in contact.

It can take time for all the roaches to inhale or come in contact with the pesticide, or a cockroach might need more pesticide to die immediately. Moreover, roaches don’t die instantly; they get sluggish, moving around more, then dying later.

You should wait 24 hours before writing off the treatment as a failure.

If the roach infestation does not seem to go down even after a day, you can use more foggers or take other measures.

5. Add Another Insecticidal Spray

Add Another Insecticidal Spray

As we said, bombing is not a 100% effective method, especially not for a large area. Combine bug bombs with a pesticidal spray or cockroach bait stations to perk up the roach-killing effect.

After treating the room with bombs, use spray near the cracks and crevices, around appliances, and inside narrow cabinets and drawers.

You can also place bait stations around devices or where roaches appear more.

Even if you don’t see many roaches after the bombing, combining another pest control method will help to prevent re-infestation.

6. Check for Outside Infestation

Outside Infestation

No bombing or other pest control will work for long if your adjacent area also has an infestation. It is particularly true for apartments, where usually the entire block suffers from roaches.

If that’s the case, try to conduct bug bombing in the entire area to eliminate the whole troop of roaches.

If it is impossible, seal all the cracks and gaps in windows, doors, and walls. Ensure there is no entry allowed for the outside infestation into your home.

7. Apply Diatomaceous Earth

Apply Diatomaceous Earth

Diatomaceous earth is a white powder that works as a natural pesticide.

It is highly effective against insects with exoskeletons, including roaches. It breaks down their external skeleton upon coming in contact with the insects, essentially killing them.

You can sprinkle Diatomaceous Earth around the area where the roach infestation is large. It can help eliminate insects that were not affected by the insecticide. However, it does not work in a wet environment, so apply it in dry areas.


It is a good sign if you see a sudden surge in roaches after the bombing. It means they are anxious and moving around and will ultimately die.

However, bug bombs are not fully effective pest control, so you might see roaches that survived the attack. Combining other pest control methods with bombing can help eliminate them.

Moreover, keep your house clean and seal the gaps and openings to prevent a re-infestation.

Frequently Asked Questions

Do Killing Roaches Attract More Roaches?

Yes and no; killing roaches can both attract and repel other cockroaches. When a cockroach dies, it releases a death smell, alerting other roaches to stay away.

However, since the insects are cannibalistic, the smell of the rotten corpse of a cockroach attracts more of them to scavenge it.

Does the Roach Infestation Worsen After the Bombing?

Roach infestation does not get worse with the bombing. It might seem that the roaches are increasing, but it is normal. Bug bombs make the cockroaches lose their mind and move around hurriedly, looking for new habitats.

If treatment is working correctly, you will see more roaches before they disappear once and for all. 

Does bombing Kill 100% of Roaches?

No, bombing does not kill all the roaches. It mainly kills insects on the surface and in the air. But bug bombing is straightforward and gives you a good headstart on full-fledged pest control.

Cockroach gel bait stations are the most effective method of killing all roaches.

How To Know if All the Roaches Are Eliminated?

The most obvious sign is that you won’t find live cockroaches around. You might spot a few dead bodies. A particular misty smell associated with roaches will not be there anymore.

Moreover, you can check the areas where the infestation was large. 

What To Do After Bombing the Roaches?

Open all the windows and doors after some time of the treatment to bring fresh air in and expel pesticidal particles. Clean all the surfaces, such as kitchen counters, furniture, walls, and floors.

Also, clean your clothes, sheets, and covers. Leave the hidden spots uncleaned; the remaining pesticide will gradually kill the hidden cockroaches.

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