Sudden Appearance Of Cockroaches? 7 Reasons Why

The sudden appearance of cockroaches in our homes or business premises is a cause for concern for everyone. Not only do roaches carry disease, but they may also cause allergic reactions. They are unattractive and difficult to get rid of. For these reasons, they are known to cause considerable anxiety and panic whenever they appear.

Sudden Appearance Of Cockroaches_ 7 Reasons Why

Whilst 1 cockroach does not necessarily mean an infestation, a sudden appearance of cockroaches probably will be!

Cockroaches are nocturnal animals, and they come out of their hiding places to feed at night. During the day, they hide away in crevices and cracks, but they ooze a characteristic odor that is easy to identify.

They also produce dark brown cylindrical droppings, and they create smear marks along the floor surface as they crawl around the floor. If they have been on your premises for any length of time, you will notice shed skins of maturing cockroaches as they become adults.

The sudden appearance of cockroaches – What are the causes?

Several things can cause cockroaches to appear suddenly on any premises, and it is important to know about these because this will help get rid of them and keep them away.

They require three important things to survive in any environment, and these are usually central to their ability to thrive wherever they are. These are food, water, and warmth. It is worth knowing this!

Sudden Appearance Of Cockroaches_ 7 Reasons Why Infographic

1 Food

Food is the biggest thing that attracts cockroaches, and maybe the reason there is a sudden appearance! Have you changed anything about the way you store food? Do you keep food outdoors?

Any type of food, from human food, pet food, to fabrics and paper including cardboard and all forms of packaging materials, cockroaches are endowed with organs of mastication to devour them all.

The sudden appearance of these pests could indicate some form of laxity in the way food items are handled in the home.

It is important to ensure food containers are well covered and, if possible, tightly sealed to prevent access to cockroaches. Food items such as bread, fresh fruits, and vegetables should be taken off the table and stored in secure locations, and you should sweep food crumbs off the floor after cooking.

Dirty dishes that may contain food remnants should not be left in the sink, and you should empty the bottom of dishwashers of any food waste.

2 Garbage Containers

Garbage containers make a very comfortable habitat for cockroaches, and if they do not have secure lids, they may constitute a real nuisance.

Cockroaches thrive in warm and humid areas especially if such places provide them with easy access to food.

When cockroaches suddenly appear in the home, this may be a pointer to the vulnerability of your garbage containers.

Ensure that the container lids are tight-fitting and that they are regularly emptied so that the strong odor emanating from them does not attract cockroaches.

3 Paper Products

Paper items such as cardboard, newspapers, and paper bags readily attract cockroaches because they easily absorb a certain type of chemical called pheromone, which is emitted by cockroaches to invite other cockroaches to a particular location.

The sudden appearance of roaches could be an indication of unsecured or open bags or the presence of boxes containing groceries and other food items.

It may be time to have these items disposed of.

4 Watering Holes

Cockroaches thrive easily where they have access to water, and this does not have to be a lot either! This is why cockroaches can be found in places where there is a source of water, such as drainpipes, the condensation around them, pet-water bowls, plant containers, and even drip plates beneath refrigerators.

Therefore, these locations (including places underneath sinks and appliances) must be kept dry at all times.

Leaky pipes should be taken care of, and drains should be well covered to prevent access to cockroaches.

5 Neighborhood Sources

Occasionally a neighborhood source may be the cause of their sudden appearance.

Occupants of multi-unit homes do not have control over the way their neighbors handle their own garbage. You may suddenly begin to experience the presence of cockroaches in parts of your home, such as your living room, where you do not eat or have any items that may be potentially attractive to pests.

Your neighbor could be the source of these cockroaches. It may be advisable to have a friendly discussion with the neighbor about the existence of the unwanted visitors and agree on a common line of action.

In addition, the installation of door guards can be useful in keeping out these pests.

6 Accidental Transportation

There is every possibility that cockroaches are accidentally transported into the home through moving boxes and such other containers, even if your home is spick and span.

Cockroaches can survive for many months in clean environments. It is advisable to clean out the area, dispose of any infested items, and undertake general sanitation to eliminate the pests.

I once accidentally bought back a roach from a Florida vacation! I knew it was in the case just after my wife let out a high pitched scream as she opened it…

7 The Attic

Boxes and other items left sitting in the attic for a long time can be the reasons why there is a sudden appearance of cockroaches. Especially if it is not cleaned out regularly or the attic environment changes suddenly and becomes hot and humid.

A leaking roof or drain pipe may cause this sudden change, and the solution would be to find the source of the water and deal with it.

Frequently Asked Questions


Is one roach a sign of infestation?

Just because you have seen one roach, it does not mean that you have to deal with an infestation. In does mean that you have to keep a very close eye out for any more though!

Why do I have roaches in my clean house?

Roaches are attracted to food, warmth, and protection. It does not matter how clean your house is, roaches just need to be able to get in to it. Even if you have a clean house, you still might have to deal with a sudden appearance of cockroaches!

Why do I suddenly have cockroaches?

The are 7 reasons on this page to help you understand why there has been a sudden appearance of cockraoches in your home. Are you storing more food? Is your garbage overflowing? Does your neighbor also have a problem with roaches? You should check these things out immediately.


The sudden appearance of cockroaches can be unsettling, so it is vital to maintain a high level of sanitation around the home all the time.

Garbage should be impossible for a roach to access and should be taken out regularly. It would be best if you cleaned appliances such as microwaves and refrigerators from time to time. Avoid bringing boxes or cases into your home that may have been sitting in the attic or similar locations for a long period of time without first disinfecting them.

Good luck!


About the author

DIY Pest Control Enthusiast Since 1996

After spending the entire night lying awake in a cockroach-infested hotel, I have driven myself to build knowledge on all things pest control. Since then, I've tested pest control techniques to see what works and what doesn't. Now, here I am giving you all the info I have learned!

10 thoughts on “Sudden Appearance Of Cockroaches? 7 Reasons Why”

  1. I would like to know about getting rid of German roaches from my car. I saw one bit soon realized my car was infested. Im sick over it!!!

    • Thanks for getting in touch! I’ll write up a guide for this but in the meantime, you should:
      1. Make sure your car has no food in it
      2. Make sure there are no collections of water
      3. Set some roach traps
      4. Check around the vehicle for entry points and remove them

      You should also set up some traps for those that are in your car. The hungrier they are, the more successful the traps will be!

      Good luck!

  2. Hi. I have noticed a problem within the past two day yesterday and today I saw a total of 5 to 6 roaches. I killed 3 in the living room. Two yesterday and I killed one today. At the front door yesterday I saw but before I could get to it went outside so I’m unsure if it came back in. I saw another today in the bathroom but it quickly went into the door hole where the door closes but as a panic I sprayed bleach and soap down it hoping to reach it and I saw one more yesterday on the stove but I also failed to catch it as I went to wack it ran quickly behind the stove. I’m not sure if I’m on an infestation level or not since yesterday I done a very deep clean but still saw some today. I checked for egg sacs nothing. So is there anything I could do should I get the landlord (cause I rent) to call an exterminator. Im not even sure how I got them I have a speculation that they came in my part from the neighbors upstairs cause out of the 7 years I been here maybe 1 roach popped up during that span. Also these are German roaches to be specific

    • Hey Nick – thanks for getting in touch!

      The first thing you should do is call your landlord. Depending on where you are in the world, they are likely to be responsible for getting rid of the cockroaches.

      Secondly, I would consider setting some cockroach traps to catch the ones who are getting in. Sticky traps work very well, lay some down in your kitchen if the exterminator can’t come out immediately.

      Good luck!

  3. Having owned my San Francisco East Bay home since 2004, I just found for the first time a cockroach. Could ongoing extreme heat waves and dangerous wild fire smoked unsafe air quality be the cause? Could this past week’s gardener-installed mulch be the cause? Or could the cause stem from a community pool left stagnant with algae, surrounded by fallen palm debris and trash containing food?

    • Hey Louis – sorry to hear that you are having issues with these annoying pests!

      The quick answer is that cockroaches are attracted to many things, including mulch and a water supply. That doesn’t necessarily mean they are attracted to the specifics you mentioned in your comment.

      The best thing to do is narrow down on the source. If there is a large collection of roaches in one of the areas mentioned, then it naturally points to it being a contributing factor.

  4. Hi:
    I have had exterminators spray twice, the 2nd time 4 days ago. Now I am seeing them in my livingroom and killed 3 tonight. I have put Pyrethrin powder around the baseboards in my livingroom and bedroom. Not sure if it helping. Any ideas would be greatly appreciated.

    • Hey Al – sorry to hear that you have cockroach issues. I’ve been there too!

      If it were me, I would purchase some sticky roach traps and lay them down in common areas such as: Under the kitchen sink, behind cabinets, along the baseboards in the living room and bedroom. I would also hunt around your home for entry points too, it sounds like they are getting in from somewhere. Find that place and seal it up quickly.

      Other than that, you could speak to the exterminators to see if they offer a guarantee, or find a pest control company that will offer that.

      Good luck!


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