Where Do Cockroaches Come From?

  • Written By Dan Edwards on November 16, 2018
    Last Updated: November 25, 2020

Have you ever got up in the night for a glass of water and encountered a scared cockroach running across the floor as you turn on the lights? Not only are we creeped out, but we’re also left with one big question: how did it get there? Let’s take a look at where roaches come from and how they get inside.

Where Do Roaches Come From?

The answer to this question depends on many factors, including the species of cockroach, the environment and the weather conditions. Some cockroaches will spend their whole life either indoors, or hitchhiking between locations.

Other roach species prefer to live outdoors, yet will move from their natural habitats into indoor environments, in search of food or warmth.

Roaches in Sewers

Many roaches are found in sewers. Living in sewers, cockroaches will feed on anything that they can find. Here they will typically eat sewage, though they have been known to feed on live baby mice.

Cockroaches move around constantly, and they will quickly make their way out of the sewer in the hope of finding other foods. They will climb vertical pipes and other exit points expertly, using the sticky pads underneath their feet.

The roaches will make their way into residential areas, where they typically find a good place to nest and start an infestation.

When they come from the sewers, cockroaches bring a whole lot of bacteria and parasites with them. Luckily for us, they rarely, if ever, bite people. Although, some species have the ability to do so.

Biting is not the only way to spread infections, though. Cockroaches have many small spines on their legs, and these pick up bacteria as the insect walks. When a roach comes into our home and casually wanders over food, that food can become infected.

Eating food which a cockroach has been in contact with can result in food poisoning.

Roaches in Basements

Damp basements are also a common place to find roaches, who will soon make their way into your kitchen. Cockroaches can actually live quite some time without food, as long as they have a reliable source of water.

In basements, cockroaches will feed on anything they can find. Old books, cardboard, and other dead insects are all potential sources of food.

How Do Roaches Get in the House?

Finding an unwanted bug in your home is never fun, it often makes us second guess how well we clean our homes. Roaches will come inside for various reasons, and it’s not always because the house is dirty. Cockroaches are attracted to warm, dark places with a good source of food. If your home is like most and offers this, then you are at risk.

When you’re moving from one house to another, you could actually bring some of the cockroaches that were living in the old house. They hide in the cardboard boxes or appliances that you’re relocating.

You might also move into a house where there’s already an infestation going on. Getting the house inspected before buying or moving in is essential.

Some cockroaches will make their way into our homes from outside. They will climb in through an open window or door, or they will find a way in via the pipes and plumbing. Some roaches are also able to fly.

Cockroaches can also leave scent trails for other roaches. These trails let their family members know that they have found a viable food or water source.

German cockroaches, the most common species in the US, prefer the warmth a home provides, and will travel from house to house. They are often found in multi-unit apartment buildings. Here, the apartments share pipelines, making a highway of sorts for roaches to travel from one place to the other. The German roach can make its way through the tiniest of openings.

The brown-banded cockroach is another very common house roach. These prefer drier locations. They are often found in high areas such as overhead cabinets. They most likely found their way inside by hiding in items brought into the house.

Cockroaches In House

Oriental cockroaches prefer the outdoors, but can make their way inside through sewer drains. Outside, they will feed on wood chips and mulch. They can hide in wood piles and could be brought indoors when you collect logs for the fire.  Inside your house, they love to feed on any starchy food. These roaches prefer cooler, darker areas. You can find them anywhere near leaking pipes or under washing machines.

The American cockroach likes to hang around restaurants, bakeries and grocery stores. These places always have an abundance in food, not to mention all the leftovers in the garbage. This species is most often found in sewers, which makes it even worse when they inhabit a restaurant.

They like to live in warm areas, typically near boiler rooms, steam tunnels, and basements. American cockroaches usually make their way into our homes by climbing up from the sewers. They will also crawl under doors, windows or enter a house through the garage.

How to Prevent Roaches from Entering Your Home

For the majority of us—if not everyone—roaches are creepy pests and we don’t want to share our homes with them. Even if you don’t mind cockroaches, remember that they bring in unwanted and potentially harmful bacteria. For this reason, it’s best to prevent them from moving inside.

Most cockroaches will find their way into our home through small cracks and openings. Roaches like the American and the oriental species will often travel through pipes and emerge in the drains. Keeping drain covers tightly closed at all times is crucial. Traps can be added around drainage areas if any of the insects are spotted.

Water pipes that come from the walls or floor should also be sealed. Make sure there are no cracks allowing roaches to enter. Sealing any holes is especially important if you live in an apartment building. A neighbor might have an infestation, which can soon move to you in this way.

Use insect screens to close off windows and doors. All exposed openings should be kept shut during the night, as this is when most cockroaches are active. If there is a gap under your door, use a door sweep to stop them entering this way.

Fill wall cracks with caulk. Steel wool is effective for larger holes. Tightly pack it and stuff it in cracks or openings, then fill with foam insulation. The insects can’t crawl through it. This is, however, only a solution in dry areas, as steel wool will rust.

The number one thing you can do to prevent roaches is to keep your home clean. Always store garbage in closed bins, and remove it regularly to prevent any odors. Cockroaches love damaged fruit, therefore, avoid having an old apple or banana laying around. You might be inviting an unwanted guest or two for dinner.