You clean the kitchen every day, and cockroaches still appear! That is what many people complain about, and the reason is that cockroaches do not come because of dirt alone, but because your home offers them three things: food, water and a hiding place. Once you know where they enter and what attracts them, preventing them becomes much easier.
In this article we explain why cockroaches appear in clean and dirty homes alike, how they reach your home from outside, and why some species prefer the kitchen while others prefer the bathroom and the drains.
Reason one: Food. Cockroaches need only very small amounts of crumbs, grease and starch.
Reason two: Water and moisture. A cockroach can live for weeks without food but cannot last more than a few days without water.
Reason three: Hiding places in cracks, behind appliances and in cartons.
Ways in: With cartons and purchases, from neighbors through pipes, from the drains, and with used furniture.
Best time to act: At the first cockroach you see: cut off the three causes, seal entry points, then use bait.
Reason one: food everywhere
Cockroaches eat almost anything, but they love crumbs, grease and starches, and very small amounts are enough for them.
- Crumbs under appliances: Under the stove, refrigerator and microwave, unseen residue collects.
- Uncovered food: Sugar, rice, bread, and pet food left out all night.
- The trash can: One that is open, not emptied daily, or without a tight lid.
- Grease: The sticky film around the stove, the range hood and the kitchen entrances.
- Soaking dishes: Dishes left in the sink overnight offer a meal and water together.
Reason two: water and moisture
A cockroach can live for weeks without food, but it cannot last more than a few days without water, so you find it near damp sources.
- Leaks under sinks and bathroom pipes.
- Condensation on air conditioner and refrigerator pipes.
- Unused drains where the trap water has dried out.
- Water collection trays under appliances and plant pots.
Fixing a small leak may cut off their lifeline faster than any pesticide. For large moisture-loving species such as the American cockroach and the Oriental cockroach, this is decisive.
Reason three: hiding places
Cockroaches like narrow cracks that touch their bodies on both sides, where they feel safe.
- Cracks behind cabinets and drawers and around pipes entering the wall.
- Stacked cartons and old newspapers.
- Inside warm appliances such as motors, electrical panels and microwaves.
- Gaps in cracked tile and behind wall panels.
Species such as the brown-banded cockroach prefer warm, dry, high places, which explains their presence in bedrooms and upper cabinets.
How do cockroaches get into your home?
Even the cleanest homes can be entered by cockroaches in ways you would not expect:
- With purchases: Grocery cartons, bags of water and drinks, and canned goods; a single carton can carry whole egg cases.
- From neighbors: In apartment buildings they travel through shared pipes and utility openings and under doors.
- From the drains: Large species climb up from the sewer and come out of uncovered openings.
- With furniture and appliances: Especially used ones, which may bring a colony with them.
- Doors and windows: Gaps under doors and no door sweep.
- From people: Bags, storage boxes and equipment coming from an infested place.
That is why we advise inspecting cartons before bringing them in and unpacking them outside the kitchen. In our article on the signs of a cockroach infestation we explained how to tell whether an entry has turned into a settled colony.
Why does each species prefer a particular place?
- The German cockroach: Loves warmth and moisture, lives in kitchens and bathrooms and breeds quickly.
- The brown-banded cockroach: Spreads through the whole house and is often found in high, dry places.
- The Oriental cockroach: Prefers cool, damp places such as basements and sewers.
- The American cockroach: Lives near drain pipes, boiler rooms and warm, damp places.
Daily habits that attract cockroaches without you noticing
- Leaving dirty dishes or juice glasses in the sink overnight; sugary and greasy residue is enough for them.
- Storing empty bags and cartons under the sink or in the storeroom for a long time; they are a perfect hiding place.
- Leaving pet food and water on the floor all night.
- Neglecting the small trash can in the bathroom or laundry room.
- Not fixing a small leak under the sink because it "is not causing a problem".
- Taking grocery cartons straight into the kitchen without checking them.
Changing these habits costs little, but it changes what cockroaches find in your home, so they look for another place.
How do you know the causes have not been fixed yet?
- Very small cockroaches appearing weeks after the first treatment point to egg cases or a hiding place that has not been found.
- Appearing only in the kitchen suggests the attraction is food or water, and appearing only in the bathroom suggests moisture and the drains.
- Appearing in large numbers by day usually means the hiding places are full.
Is cleanliness alone enough?
Cleanliness is necessary but not enough. It reduces food and makes gel more acceptable to cockroaches, but as long as water, a hiding place and an entry point exist, they will come back. In short: cleanliness stops the problem from getting worse, and proper treatment ends it.
- Cleanliness: Deprives cockroaches of food and makes bait their first choice.
- Sealing entry points: Prevents re-infestation from outside.
- Bait and monitoring: Eliminates the population that is actually there.
The full plan is in getting rid of cockroaches for good, and the prevention steps are in cockroach prevention.
How to inspect your home to find the causes
Make the inspection systematic, room by room, which is faster than searching at random:
- Kitchen: Check under the stove and refrigerator, behind the washing machine and inside the lower cabinets, and note where the trash and pet food are kept.
- Bathroom: Check drain openings, the pipes under the sink and any leak or constant dampness.
- Storage rooms: Check cartons stacked on the floor, old bags and stored furniture.
- Entrances: Check the gaps under doors and the cracks around pipes and windows.
You can place small glue traps in these spots for a night or two; the number of cockroaches caught and where tells you where the main hiding place is.
Quick steps to cut off the three causes
- Remove crumbs and grease daily, seal open foods in airtight containers, and pick up pet food at night.
- Take out the trash daily and use a bin with a tight lid.
- Fix leaks and dry sinks and damp surfaces before bed.
- Seal cracks around pipes and doors and fit a door sweep under doors.
- Unpack cartons outside the kitchen and dispose of them quickly instead of storing them.
- Only then use a suitable bait, follow the product label and instructions, and place it out of reach of children and pets.
When to call a professional
If cockroaches persist after weeks of cutting off the causes and using bait, or if they appear in several units of the building, ask a licensed pest control company to inspect and identify the shared source. To learn about their harms, see our article on the harms of cockroaches; for the full overview, the cockroach guide; and browse the Pest Library for the rest of the guides.
Products that treat both the cause and the symptom
- Catch Master American glue trap, ready to use for mice and crawling insects, 72 glue boards: Glue traps we place at entrances and under sinks to find out where cockroaches come from.
- Professional pack for controlling German cockroaches at home: A professional pack for the German cockroach: Fort gel, Advion gel and a 1.5-liter sprayer, treating the source and the hiding places.
- Professional pack for controlling American cockroaches at home: A professional pack for the large American and Oriental species that come up from the drains.
- Cockroach gel section: All the international gels we carry in one place.
Frequently asked questions
Why do cockroaches appear in a clean home?
Because they may arrive with cartons, from neighbors or from the drains, and find water and a hiding place. Cleanliness reduces what attracts them but does not stop them entering.
What attracts cockroaches the most?
Water and moisture first, then crumbs, grease, uncovered food and warm, dark places.
Do cockroaches come from the sewers?
The large species, the American and the Oriental, do; the German cockroach usually arrives with purchases or from neighbors.
Do cockroaches come from cartons?
Yes, it is one of the best-known ways they spread, because cartons are warm and carry egg cases, so we unpack them outside the kitchen.
Does light attract them?
No, most of them flee from it, although some winged species may be drawn to lights at night.
Why don't they go away after I clean?
Because the eggs and nymphs are in the cracks, and surface cleaning does not reach them. You need bait that reaches the hiding places.
Do cockroaches come only from dirty homes?
No. Clean homes can be entered by cockroaches through cartons, pipes, drains and cracks, but cleanliness reduces what attracts them and makes treatment more successful.
How long until I see results?
It varies with the size of the infestation, but cutting off the causes and following up weekly for several weeks is the usual way to get things stable.