Household pests
Cockroaches: how to identify them and when to call a pro
Cockroaches are flat, oval, fast-moving insects that hide in warm, humid places and come out at night. They can contaminate food and are linked to allergies and stomach illness, so an infestation is a health concern. Because they breed quickly and hide well, cockroaches almost always need professional pest control to clear.
- Also known as
- German cockroach, Blattella germanica, Oriental cockroach, Blatta orientalis
- Easily confused with
- large beetles, crickets, bed bugs (nymphs sometimes confused)
- How serious
- High: a health risk that almost always needs professional treatment
- Typical cost
- Professional cockroach treatment commonly runs from around 100 to 300 pounds, often over several visits
How to identify cockroaches
German cockroaches are small (12 to 15mm), light brown with two dark stripes behind the head, and prefer warm, humid kitchens and bathrooms. Oriental cockroaches are larger (20 to 30mm) and dark, almost black, and like cooler, damp places such as drains, basements and outdoor areas.
Cockroaches are nocturnal, so seeing them in daylight can indicate a heavy infestation. Other signs are droppings (like ground pepper or small dark smears), egg cases, shed skins, and a musty, oily smell.
How serious is it?
High: a health risk that almost always needs professional treatment
Cockroaches are a recognised health concern. They move between waste and food, can contaminate food and surfaces with bacteria, are associated with stomach illness, and their droppings and shed skins are a known trigger for asthma and allergies.
They also breed quickly and hide in inaccessible voids, behind appliances and in drains, which is why infestations rarely clear with shop products alone and tend to return if not treated thoroughly.
How to fix it yourself
- Tighten hygiene immediately: clear food debris, store food in sealed containers, fix leaks and reduce humidity, and empty bins regularly. This slows them but rarely clears an infestation alone.
- Reduce harbourage by sealing cracks and gaps behind units, around pipes and appliances, and in skirting.
- Use cockroach monitoring traps to confirm species and spread before treatment.
- Do not rely on supermarket sprays for an established infestation, as they seldom reach the hidden breeding sites and can scatter the population.
When to call a professional
- Almost any confirmed cockroach infestation, because they breed fast, hide well and carry health risks.
- Seeing cockroaches in daylight, finding egg cases, or any sign of spread, which point to an established population.
Who to call
- A BPCA or NPTA member pest controller for gel baiting and a full treatment programme.
- Your local council pest control or environmental health service, which treats cockroaches in some areas and acts where there is a public health concern.
Indicative cost: Professional cockroach treatment commonly runs from around 100 to 300 pounds, often over several visits. Prices vary by area, severity and access, so always get a written quote.
Frequently asked questions
Can I get rid of cockroaches myself?
Improving hygiene, sealing gaps and using monitoring traps helps, but cockroaches breed quickly and hide in voids and drains, so shop sprays rarely clear an infestation. Almost all established cockroach problems need a professional pest controller to treat fully.
Are cockroaches a health risk?
Yes. Cockroaches can contaminate food and surfaces with bacteria, are associated with stomach illness, and their droppings and shed skins can trigger asthma and allergies. This is why a cockroach infestation should be dealt with promptly.
What attracts cockroaches to a house?
Warmth, humidity, food debris and water draw cockroaches, especially in kitchens, bathrooms and around drains. They can also be brought in with packaging, appliances or second-hand goods, or move between flats through shared pipework and walls.
Does seeing one cockroach mean an infestation?
Not always, but cockroaches are nocturnal and hide well, so seeing one in daylight can mean numbers are high. It is worth setting monitoring traps and acting early, as a small problem can grow quickly if left.
Sources
Editor, HomesAndHedge
Oliver leads HomesAndHedge's editorial coverage of home and garden problems. He researches and writes the plain-English explainers on pests, invasive plants, damp and mould, drainage and wildlife, drawing on guidance from bodies such as the Property Care Association, the RHS and the NHS, and is clear about when a job needs a qualified professional.
Last reviewed: 8 June 2026