To get rid of cockroaches, combine three things that actually work: gel bait placed in the cracks where roaches hide, relentless sanitation that cuts off their food and water, and a desiccant dust in wall voids and under appliances. Then monitor with sticky traps and seal entry points. The one thing to skip is foggers — research shows “bug bombs” don’t reach roach harborages and can make the problem worse.
Key Takeaways
- Gel bait is the core treatment — it spreads through the colony by a domino effect.
- Sanitation is non-negotiable — roaches can’t thrive without food and water access.
- Desiccant dust in voids (boric acid or DE) adds a slow, resistance-proof kill.
- Skip foggers — they miss the cracks roaches live in and can scatter them.
- Never spray over bait — repellent sprays drive roaches off the bait and waste it.
- Persistence wins — re-bait and monitor for several weeks to catch newly hatched roaches.
A roach-control plan that works (in order)
Step 1: Sanitation — starve them out
Cockroaches need food, water, and shelter. Take those away and every other treatment works better:
- Clean up food residue nightly — counters, stovetop, under appliances, and crumbs in cracks.
- Store food (including pet food) in sealed containers, and don’t leave dishes out overnight.
- Fix leaks and dry out sinks — roaches will travel for water, and a dripping pipe sustains a colony.
- Take out the trash in a sealed can, and reduce cardboard clutter (a favorite harborage).
Step 2: Gel bait — the main weapon
Gel baits are the most effective consumer tool against German cockroaches. A roach eats the bait, returns to its hiding spot, and the active ingredient spreads to others through droppings and cannibalism — the “domino effect” (UC IPM: Cockroaches). Place small dabs in cracks, hinges, under sinks, and inside cabinet corners — not on open floors. See our guides to the best roach baits and the pro-favorite Advion gel bait.
Critical: don’t spray insecticide over or near your bait. Repellent sprays push roaches away from the bait and undo it.
Step 3: Dust the voids
Add a desiccant dust — boric acid or diatomaceous earth — as a thin, almost invisible layer in wall voids, under and behind appliances, and in cracks. It kills slowly but roaches can’t develop resistance to it (does boric acid kill roaches? and our best roach powders). A thick pile just gets avoided — less is more.
Step 4: Add an IGR for heavy infestations
For stubborn or large infestations, an insect growth regulator (IGR) stops young roaches from maturing and reproducing. It doesn’t kill on contact; it collapses the colony’s ability to rebound, working alongside bait.
Step 5: Monitor and seal
Place sticky traps along walls and in corners to track where roaches travel and whether numbers are dropping. Seal cracks, gaps around pipes, and entry points to keep new roaches out and force the survivors onto your bait.
What doesn’t work (and why)
- Foggers / “bug bombs.” They release pesticide into open air, missing the cracks where roaches actually live, and can scatter the infestation. They’re also flammable. (The honest fogger breakdown.)
- Spraying over bait. Repellent sprays and bait work against each other.
- Sanitation alone. It weakens a colony but rarely eliminates an established one — pair it with bait.
German vs. American cockroaches
Most indoor infestations are German cockroaches — small, fast-breeding, and the hardest to clear; bait-and-sanitation is the proven approach. American cockroaches (the large “palmetto bugs”) often come in from outside, drains, or sewers, so they also need exclusion and treatment of entry points. Knowing which you have shapes the plan — signs of a cockroach infestation helps you identify them.
When to call a professional
If the infestation is large, keeps rebounding after weeks of baiting, or you’re in a multi-unit building (where roaches travel between units), a licensed pro with access to professional baits and IGRs is the efficient choice.
Why it’s worth doing right
Cockroaches aren’t just unpleasant — their droppings and shed skins are a known trigger for asthma and allergies, especially in children (CDC: Cockroaches and Asthma). Clearing them is a health improvement, not just a comfort one.
Frequently Asked Questions
What kills cockroaches permanently?
There’s no single product, but the combination that gives lasting results is gel bait plus thorough sanitation plus a desiccant dust in voids, followed by sealing entry points. Bait kills the colony; sanitation and exclusion keep new roaches from re-establishing.
How do I get rid of roaches fast?
Start with gel bait in the cracks where roaches hide and remove all food and water access the same day. Bait begins working within days and spreads through the colony. Avoid foggers and sprays, which feel fast but don’t reach the harborages.
Why do I still have roaches after spraying?
Likely two reasons: German roaches are resistant to many sprays, and spraying over bait repels roaches from the one thing that would actually kill the colony. Switch to a bait-and-sanitation approach.
Are cockroaches a health risk?
Yes. Cockroach allergens in droppings and shed skins are a recognized trigger for asthma and allergic reactions, particularly in children. That’s a key reason to treat an infestation promptly rather than tolerate it.