Where Do Cockroaches Come From & What Attracts Them?

If you’ve spotted a cockroach in your home recently, you might be concerned about how it got in—and perhaps the possibility that there’s more of them hiding in places that you can’t see. 

Cockroaches are ubiquitous in densely-populated urban areas like New York City. Fortunately, seeing a single roach doesn’t always mean you’ve got an infestation on your hands. It’s also possible that it’s a loner that managed to sneak its way inside.

Roaches manage to get inside our homes in a number of ways, and knowing where to look and what to do to keep them out will help keep your home cockroach-free. 

Where Do Cockroaches Come From? 

The most common species of cockroaches that terrorize homes and businesses in NYC are American and German cockroaches. Oriental and Brown-Banded cockroaches can also be found here, but they are less common.

Cockroaches generally prefer dark, humid environments where they have easy access to water and food. They can be found living and reproducing in cluttered city streets, parks, subway tunnels, and sewer systems—as well as inside houses and buildings.

The large-sized American cockroach, in particular, likes to be outside. Since they need a regular water source, they’re often seen around sewers, storm drain, gutters, and pipes.

The shiny, black Oriental cockroaches (also known as water bugs) are another species of roaches that thrive around damp, wet areas.

How Do Roaches Get in Your House or Apartment

Roaches are drawn to houses and apartments in search of food, warmth, and moisture. If you’re unlucky enough to spot one in your home, knowing how it got inside can help you get rid of them for good.

Some common ways for cockroaches to enter your home include:

• Cracks in Walls and Foundations
• Doorways
• Plumbing Lines
• Packages, Baggage, and Clothing
• Basements
• Neighbors

Cracks in Walls and Foundations

Gaps and cracks are easy entryways for roaches. Their slim, flat bodies allow them to fit into very small crevices. Some species of roaches are able to squeeze into openings as narrow as 1/16 of an inch. 

If there are cracks along the walls in the inside of your home, roaches may be able to get into crawl spaces between walls, from which they can quickly travel from room to room.

We recommend using silicone-based sealants to close up any gaps and cracks in your home (both inside and outside) to keep roaches from getting in. 

Doorways

Slipping into your home underneath a door is another common way for a roach to get inside.

With their flat bodies, they can easily fit underneath an average entryway gap. This is especially true if you have a habit of leaving doors open for extended periods of time. 

If there’s a gap between the bottom of an outside-facing door and the floor, consider installing a door sweep. These tools can be easily installed, and will help block off the gap to prevent unwanted pest entry. 

Plumbing Lines

Roaches are drawn to spaces with moisture, warmth and food. Unfortunately for homeowners and renters, plumbing lines have all of these. 

These pests can enter your home’s drainage system from the sewer system, traveling through the drains that connect to your home.

They’re commonly found near shower drains and kitchen drains in particular, which tend to have a lot of water and food particles. They can also come through cracks in the wall where plumbing lines are, such as underneath sinks and behind dishwashers.

American cockroaches in particular are often associated with plumbing issues. They tend to nest in areas like boiler rooms and travel around by following pipes and water lines.

Packages, Bags, and Clothing

Cockroaches are also able to get inside your home by hitching a ride on the things you bring inside. It’s quite common for tiny German cockroaches to infest a home after being accidentally brought inside via deliveries and packages.

Because the German cockroach species is relatively small, at least compared to their American or Oriental counterparts, they can easily hide in the folds and seams of cardboard boxes, suitcases, and used furniture.  

They’re especially attracted to cardboard boxes or bags made with paper. Roaches communicate with each other with odors called pheromones that are released with their feces. Cardboard and paper absorb these odors, allowing other cockroaches to follow the scent like a trail. 

To minimize the risk of cockroaches being brought into your home this way, take the time to check any boxes or items before bringing them into your home. 

Basements

If you live in a house, a common place where roaches come in from is the basement. Cockroaches love dark and humid spaces, so if a basement hasn’t been properly insulated or isn’t properly ventilated, roaches may find their way in from outside and then spread to the rest of your house from there. 

Neighbors

If you live in an apartment building, there’s a good chance that these pests may be coming from a neighboring unit. Apartments have many shared walls, and roaches could easily move through cracks, crevices, vents, and plumbing lines.

Check with your building’s maintenance staff to see if other residents have been dealing with a cockroach infestation.  

What Attracts Cockroaches?

Cockroaches are attracted to:

• Moisture
• Food
• Warmth

Roaches can only go for about a week without water. That’s why they’re drawn to humid areas like bathrooms, basements, and kitchens. These small pests don’t need large amounts of water though—small leaks or even just excess moisture in the air can be enough to sustain them.

When it comes to food, roaches are able to survive up to a month without it. Cockroaches are cold-blooded insects, allowing them to keep their body temperature low to preserve energy. This comes in handy when they are struggling to find food.

Lastly, warmth and humidity are also important attractants for cockroaches. These pests thrive in warm environments, which is why roach sightings tend to spike in the summer. The increase in temperature pushes roaches to feed and reproduce faster than they would in the colder months. 

Tips for Keeping Roaches Out of Your Home

• Wash and put away dishes immediately—don’t leave them in the sink overnight.
• Clean up spills and crumbs as soon as possible.
• Keep a tight lid on kitchen trash and take it out on a nightly basis.
• Keep food items in sealed, airtight containers.
• Seal up leaky pipes and fix any dripping faucets.
• Vacuum floors regularly, especially in areas where food is prepared or eaten.