How to Get Rid of German Cockroaches for Good

German cockroaches are the most common indoor cockroach in the US, UK and much of the world, and the hardest to get rid of with store-bought sprays. They breed fast, hide in tiny cracks, and many populations have developed resistance to common insecticides. The good news: the right bait strategy works very well, even without a professional, if the infestation is small to moderate.

For an overview of every common household pest, see our complete pest control guide.

Step 1: Confirm it’s a German cockroach

Larger dark brown or reddish roaches (American, Oriental) usually come from drains, basements or outdoors and need a different approach — mainly sealing entry points and treating the perimeter.

Step 2: Find where they hide

German cockroaches spend most of their time packed into cracks close to food, water and warmth. Use a flashlight at night and look for droppings (black, pepper-like specks), egg cases (small brown capsules) and shed skins.

Check:

• cabinet hinges and the corners inside cabinets
• under and behind the sink, around pipes
• behind and under the fridge, stove and dishwasher (warm motors)
• inside the microwave and toaster area
• around the bathroom vanity and toilet base

Place sticky monitor traps (glue boards designed for insects) in corners of these areas. After 2–3 days, the traps with the most roaches show you where to focus.

Step 3: Bait properly

Gel bait works because roaches eat it and return to the hiding spot, where they die. Other roaches then eat their droppings and bodies and are poisoned too. Placement matters more than the brand.

• Small dots, many places. Pea-sized or smaller dots, every 12–18 inches along cracks, rather than big blobs.
• In cracks, not on open surfaces. Put bait where roaches hide: hinge gaps, the seam where the countertop meets the wall, behind appliances.
• Keep the area free of sprays and cleaners. Repellent sprays and strong cleaners on the bait make roaches avoid it.
• Rotate active ingredients if bait stops working after a few weeks — use a product with a different active ingredient.
• Re-check every week. If a dot has been eaten, replace it.

Common professional-quality gels include products with indoxacarb, fipronil, abamectin or imidacloprid as the active ingredient. We compare options in Best Cockroach Gel Baits. You can find them on Amazon or at hardware stores.

Step 4: Add an insect growth regulator (IGR)

An IGR such as hydroprene or pyriproxyfen doesn’t kill adults, but it stops young roaches from developing into breeding adults. Placed alongside baits, IGR “point sources” (small discs) help break the breeding cycle. Look for cockroach IGR point sources and place one in each heavily infested cabinet.

Step 5: Remove food, water and clutter

Bait works much better when it’s the best food around.

• Wipe counters and the stovetop every night; don’t leave dishes in the sink.
• Store food — including pet food — in sealed containers.
• Take trash out nightly; use a bin with a lid.
• Fix dripping taps and wipe the sink dry before bed.
• Remove cardboard boxes and paper bags, which roaches love to hide in.
• Clean grease behind and under the stove.

Step 6: Seal hiding places

After a few weeks of baiting, caulk cracks along baseboards, backsplashes and around pipes. Seal gaps where pipes enter walls under sinks with foam or caulk. This reduces hiding spaces and limits roaches moving in from neighbors.

Step 7: Add boric acid dust in voids (optional)

A light dusting of boric acid in wall voids, behind outlet covers (with power off) and under appliances provides long-lasting control. Use a bulb duster to apply a fine, barely visible layer — heavy piles repel roaches. Keep away from children, pets and food surfaces.

How long does it take?

Keep monitors in place for a few months. One or two roaches on a monitor is an early warning to re-bait.

When to call a professional

• You see roaches in the daytime or in many rooms (a heavy infestation).
• Someone in the home has asthma — faster control matters. See cockroaches and asthma.
• You live in an apartment and neighbors have them too — building-wide treatment works best.
• DIY baiting hasn’t made a clear difference after 4 weeks.