Cockroaches
How to Get Rid of Cockroaches for Good: What Works and What Scatters Them
- Spray kills the ones it hits and sends the rest to other rooms. It's not the right tool.
- The small one in the kitchen is the German cockroach and it breeds indoors; the big one is the American cockroach and it comes from the sewer.
- Today: dry everything, store food, use a trash can with a lid, seal the gaps around the pipes.
- What actually works at home: bait gel in small dots and fine boric acid powder in dry spots.
- It takes 2 to 3 treatments because of the egg cases (oothecae). House up to 100 m²: ₡39,900. If you have not fumigated in the last 6 months, it takes two applications and the second one is charged; the 30-day check only applies once the plan is complete.
Why spray scatters them
Aerosol insecticide kills the cockroaches it touches and repels the rest. That second effect is the problem: the ones hiding behind the stove smell the product and move to the bathroom, the bedroom, the closet. A week later you have cockroaches in three places instead of one.
Spray is good for one thing: killing the one you just saw run across the floor. It's not the tool for wiping out the colony. If you've already sprayed the whole kitchen, it's not a big deal, but wait a week before putting out gel: the repellent in the spray keeps them away from the bait.
German or American: which one do you have
The German cockroach is 1 to 1.5 cm long, light brown with two dark stripes behind the head, and lives in the kitchen: behind the fridge, in the microwave motor, in cabinet hinges, under the sink. It breeds inside the house, and a female carries a capsule with 30 to 40 eggs. It has its own page: German cockroach.
The American cockroach is 3 to 4 cm long, reddish brown, and flies poorly, but it does fly. It lives in the sewer, in the drain access box and in the patio drain, and gets in at night through the bathroom drain trap or the gap under the door. If you see a big one every now and then, you don't have a colony inside: you have an open entry point. For this one, sealing and treating the drains matters more than gel in the kitchen.
What you can do today
- Dry everything before bed. Kitchen sink, bathroom sink, bathroom floor, the drip tray under the fridge, and hang the dish towel instead of leaving it in the bottom of the sink. A cockroach can go a month without food and a week without water.
- Store food in containers with lids: bread, cereal, cookies, pet food. Clean the grease off the burners and behind the stove.
- Use a trash can with a lid and empty it at night.
- Seal the gaps around the pipes: the hole where the kitchen and bathroom sink pipes go into the cabinet, with putty or silicone.
- Get cardboard boxes out of the kitchen and the storage room. They like them for laying eggs.
More detail in sealing food and trash and in cockroach prevention in the kitchen and bathroom.
Bait gel: where to put it and how much
Bait gel is the do-it-yourself option that really works against the German cockroach. It's food laced with a slow-acting insecticide: the cockroach eats, goes back to its hiding spot and dies there, and the others eat its remains and droppings and die too. That's why it kills the colony and not just the one that ate it.
How much. Lentil-sized dots, not long lines. Lots of small dots work better than a few big ones: 20 to 30 dots in a typical kitchen.
Where. On kitchen cabinet hinges, in the inside corner of every drawer, behind and under the fridge (near the motor, which gives off heat), under the sink next to the pipes, behind the microwave and the coffee maker, where the cabinet meets the wall, under the bathroom sink. Always in cracks and corners, never on open surfaces that get cleaned or walked on.
What not to do. Don't spray insecticide or bleach cleaner near the gel: it contaminates it and they stop eating it. Don't put it on greasy surfaces. Check after 7 days: if it's gone, put more out. If it's untouched, it's in the wrong place.
Boric acid and home remedies: what works and what doesn't
Boric acid does work, on one condition: as a fine powder, in dry spots, in an almost invisible layer. Mix one part sugar with three parts boric acid and dust a thin layer behind the fridge, under the stove, at the back of cabinets, in the gap between the cabinet and the wall. The cockroach walks over the powder, cleans its legs and swallows it. If you put it in little piles, it goes around them. If it gets wet, it stops working. The dough balls made with flour and boric acid that go around online work worse than the powder and get moldy. Keep the powder out of reach of children and pets: it's toxic if swallowed in quantity. More on products in cockroach poison.
What doesn't work: bay leaves, vinegar, baking soda with sugar, cucumber, lemon peel, ultrasonic devices. None of them kills or drives away an established colony.
Oothecae: why 2 to 3 treatments are needed
The German cockroach doesn't lay loose eggs: it carries a hard capsule, the ootheca, with 30 to 40 eggs, and drops it in a crack one or two days before they hatch. No gel or powder gets through that capsule. So even if you kill every adult today, a new batch hatches in two or three weeks. The second treatment kills those nymphs before they breed; sometimes a third one is needed. Anyone who promises you a single treatment will do it either has few cockroaches to deal with or isn't counting the oothecae.
There's one case where neither discipline nor gel is enough: when you live in a building or condominium and the cockroaches come through the electrical ducts, the shared plumbing or the apartment next door. If you treat and two weeks later they come back along the same wall, the whole building needs coordinated treatment, at least the apartments that share walls and ducts. Talk to the management before spending on a fourth round of gel.
What EcoPlagas does
The technician identifies the species and the hiding spots, and applies gel in cracks and hinges, under appliances and where pipes go through. It's not spray in the air throughout the house: the product goes where the cockroach lives, not where you walk. In the drains and the drain access box, when it's the American cockroach, the entry point is treated. After the first treatment the population drops by 70 to 90%; the rest are the nymphs that hatch from the oothecae in the following weeks, which is why, if the problem persists after 30 days, the follow-up treatment is free. You can go back into the house an hour later, with the kitchen ready to use. The full service is on cockroach control.
Date confirmed in less than an hour on WhatsApp. Service 24 hours a day, every day, nationwide. Licensed by the Ministry of Health.
How much it costs
House or apartment up to 100 m²: ₡39,900 (CRC). Up to 200 m²: ₡49,900. Over 200 m²: ₡59,900. The price is based on square meters, not on how many cockroaches there are. If you have not fumigated in the last 6 months, it takes two applications and the second one is charged; the 30-day check only applies once the plan is complete. Prices on the prices page. Phone 6073-1000, WhatsApp 6030-0045.
Frequently asked questions
Why do cockroaches show up in other rooms after I use bug spray?
Because spray repels them: the ones hiding in the kitchen move to the bathroom and the bedrooms. To wipe out the colony, use bait gel in cracks, which doesn't scare them off.
How much bait gel should I use, and where?
Lentil-sized dots, 20 to 30 in a typical kitchen, on hinges, in drawer corners, behind and under the fridge and next to the pipes. Never on open surfaces.
Why are 2 to 3 treatments needed?
Because the eggs are inside a capsule (ootheca) that no product can get through. Nymphs hatch two or three weeks later, and the second treatment kills them before they breed.
How much does it cost to get rid of cockroaches in a house?
Up to 100 m², ₡39,900; up to 200 m², ₡49,900. If you have not fumigated in the last 6 months, it takes two applications and the second one is charged; the 30-day check only applies once the plan is complete.