What do I need for German cockroaches, and in what order?

You do not need a kit with ten things in it. For German cockroaches, the standard approach uses three: gel bait, an insect growth regulator and monitor traps. Add a tube of sealant if you have gaps to fill. That is the list. The order you use them in matters more than the brand on the box.

The three things, and what each one does

• Gel bait does the killing. Cockroaches eat it, go back to their hiding places, and pass it on to the others. It comes in a syringe or tube so you can put small dots right into cracks.
• An insect growth regulator stops young cockroaches growing into breeding adults. It is slow on its own and powerful alongside bait. It comes as small discs or stations, sprays, and in some baits. See what a growth regulator does.
• Monitor traps are folded sticky cards. They do not end anything. They tell you where cockroaches travel and whether the numbers are falling. See how to use monitor traps.

What to leave on the shelf: surface sprays and foggers, which scatter cockroaches and spoil bait, and the things that do not do the job at all, like peppermint, baking soda and ultrasonic plug-ins. More in home remedies and ultrasonic repellers.

The order

1. Clean and starve. Grease off the cooker sides and the wall behind it, crumbs from under the fridge, food into sealed tubs, bin out at night, sink dry, pet food picked up overnight.
2. Traps down first. Flat against walls under the sink, behind the fridge and cooker, in the bathroom. Your first count is the starting line.
3. Bait the hiding spots. Small dots on cupboard hinges and corners, around pipes under the sink, behind appliances, and behind the kitchen units. Many small dots beat a few big ones. Keep it off surfaces you wipe.
4. Add the growth regulator where the label says, usually in cupboards and near where you have seen young ones.
5. Track weekly and top up. Count the traps on the same day each week. Replace bait that has been eaten or dried out, as often as the label allows.
6. Seal as you go. Gaps around pipes, a broken kickboard, the gap by the cooker. See sealing gaps.

For every product: follow the label, and check it is allowed where you live. The label decides how much, where and how often.

Behind the kitchen units

You do not need to rip out the kitchen. Most units have a kickboard, the strip along the floor under the cupboards, that clips or screws on. Take it off, vacuum behind it, put bait dots along the back edges and corners, set a trap in there, and refit it. If it is broken or there is a gap beside the cooker, fix or block it once the numbers drop. That one space is often where they live.

Kids and pets: gel goes into cracks, behind appliances and high inside cupboards, never on low open surfaces. Stations and traps go where children and pets cannot get to them, and if a cat hunts behind the kickboards, that spot no longer counts. If a label warns against use around children or pets and you cannot keep them away, leave that product out. If a child or pet eats bait, call your doctor, vet or local poison centre with the label to hand.

Just moved, maybe to a new country

Brand names change from country to country, and some products are not sold everywhere. Look for the product type and the active ingredient on the label rather than a brand you saw recommended online. A pharmacist, a hardware shop or a local pest controller can tell you what is available and allowed where you live.

If you rent, tell your landlord in writing straight away, with the date and photos. That protects you and may get the building treated. Our answer on just moved in and found pests covers the rest.

When to call a professional

If you are still catching young ones after four weeks of bait and a growth regulator, call a pro, and show them your dated trap counts. Not sure whether to start yourself or call one now? Read DIY or a pro.