How to get rid of cockroaches in sinks and drains

It’s never a good sign to find a cockroach in your home, as they are seldom alone. For every cockroach you see, dozens may be hiding. However, finding cockroaches in the kitchen, where food is prepared, can be especially annoying.

Cockroaches will feed on almost anything, including our waste. That’s why they love our homes. But as well as being unpleasant, cockroaches can bring dangerous germs, bacteria, and allergens with them when they enter your home.

One of the most common ways for cockroaches to enter our homes is through bathroom and kitchen drains. They don’t stray far from these areas, either, as they tend to stay close to places that can guarantee them food and water.

In this article, we will tell you how cockroaches have arrived in your home. We will also show you how to prevent and combat cockroaches in those entry points that are the drains.

Where do cockroaches come from?

They may have come with the moving boxes, or they may have been living in the house even before you moved in. But sometimes cockroaches simply come into your house by walking into your drainpipes.

Like rats and mice, cockroaches can squeeze through the smallest cracks and holes, thanks to their special anatomy. They can easily fit through narrow ducts and very narrow cracks, as they can flatten their bodies if they need to.

But if you see a cockroach near the drain or sink, it doesn’t necessarily mean that they’ve crawled in, as they may be looking for water. Nor does it mean that your house is dirty and messy. Cockroaches get in whenever they can find a hole or crevice that allows them to do so.

Not only are they very sneaky bugs, but they also know how to hide well. So, unless you catch them at night, you may not notice them until you have an infestation.

How to get rid of cockroaches in sinks and drains

How do you prevent a cockroach infestation?

Cockroaches arrive uninvited, but only stay and proliferate where they find food easily and in abundance. Eliminating cockroach access points to your home will go a long way towards preventing an infestation.

It is also important to suppress food and water sources that may attract cockroaches. To achieve this, it is important to keep kitchen countertops and appliances clean.

Never leave food on countertops or in the kitchen sink overnight. If you keep providing them with the three things they need (food, water, and shelter), they will keep coming back and attracting more companions to the feast.

This includes removing any leftover food, such as crumbs, splashes and dirty dishes left in the sink. Furthermore, be sure to use metal grates for drains, which prevent any invaders from getting through, or accessing water.

Cockroaches are nocturnal, so it is most important to keep them out at night. Rubbish bins are another place where cockroaches can find food and shelter. Be sure to keep the lid always closed and periodically take out the rubbish.

Eliminating Cockroach Entry Points

There are many things homeowners can do to make their homes less attractive to cockroaches. Here are a few tips:

Inspect and replace pipes

Check the pipes under the sink, behind the washing machine and under the sink. Any looseness in the wall is a potential entry point, or harbouring place, for cockroaches.

While caulking cracks and plugging holes may be a temporary solution, it is recommended that a professional repair or replace pipes and perform a comprehensive inspection of drains.

Fix dripping faucets

Continuously dripping taps leave small puddles that cockroaches use as a source of water. If you notice standing water in or around a tap, there may be a leak. Have a professional plumber inspect the problem and make repairs.

Fix holes in walls

Look for any holes or cracks in the walls. They can not only be points of entry, but also daytime hiding places for these nasty tenants. These holes can be filled with expanding foam insulation to seal these spaces.

Eliminate other water sources

If you eliminate several obvious sources of water for cockroaches, they will look elsewhere, such as refrigeration pipes subject to condensation. These should be protected with foam insulation and tape.

How to combat a cockroach infestation

If you have a cockroach infestation, you need to act quickly, especially if the situation continues to worsen. The following are common methods, all information shared have educational purpose, so we strongly recommend to hire professional to find the proper solution.

  • Gel baits can kill many cockroaches in one night. Be sure to place them near the places they frequent.
  • Placing glue traps around a possible entry point can help confirm that they are.
  • Clean your drains with a commercial product. In addition to killing cockroaches, they remove grease and dirt that can feed them.
  • Using chemical insecticide dusts in entry and passage areas can kill cockroaches. In addition, they will carry the impregnated substance on their bodies to their hiding places, affecting more insects.
  • Insecticide sprays can be used as long as they do not affect people or animals living in the house.

Home products to get rid of cockroaches

To control and prevent cockroach infestations, there are two natural substances that are highly effective and very safe to use: borax and diatomaceous earth. We do not recommend the use of any of them unless you are a trained professional, the best solution is to hire professional services.


The mineral borax, scientifically known as sodium borate, comes in the form of a finely divided white powder. It can be found in the formulation of cleaning products, but also as an over-the-counter powder.

If applied to the cockroaches’ places of passage, the substance adheres to their legs. Subsequently, the cockroach will ingest the borax to clean itself, when it returns to its hiding place. Once the powder is in its stomach, the substance acts like a poison.

It acts very slowly, but the number of insects will decrease week by week. Borax has no odour and is considered safe for pets. However, it should not be applied where it can be ingested by pets and babies.

Diatomaceous earth

Diatomaceous earth, also called diatomite, is a fine powder made by grinding the fossilised shells of microscopic marine animals. It is like sand, but finer and more abrasive.

Diatomaceous earth destroys the exoskeleton of cockroaches (and other insects), causing them to dehydrate. It also adheres to their legs, from where they ingest some of it. They usually die of dehydration soon after returning to their nests.

Apply it anywhere cockroaches are suspected to pass through or enter, especially under the sink and around drains. It has no odour and is harmless to both pets and humans.

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