Three cockroach species cause almost all UK infestations: German (kitchens/restaurants), Oriental (cellars/drains), and Brown-banded (warm rooms higher up). Identifying the species changes where to look and which treatment works.
- German: about 10-15mm, light brown/tan with two dark stripes behind the head; usually found in warm humid areas such as kitchens and bathrooms
- Oriental: about 20-30mm, dark brown to black and glossy; commonly found in cool damp areas such as basements, cellars, drains and rubbish areas
- Brown-banded: about 10-15mm, light brown with pale bands across the wings/abdomen; prefers warm dry elevated areas such as ceilings, cupboards, attics and behind appliances. Rare in the UK compared with German and Oriental cockroaches
- Never squash a cockroach - it can spread viable eggs
Cockroaches are one of the most resilient pests we deal with. Three species cause almost all infestations in UK homes and businesses - and knowing which you have changes the treatment plan. This guide covers the three species, how to tell them apart, and why DIY treatment almost always falls short.
UK Cockroach Species at a Glance
| Feature | German | Oriental | Brown-Banded |
|---|---|---|---|
| Size | 10-15mm | 20-30mm | 10-15mm |
| Colour | Light brown / tan, two dark stripes on pronotum | Very dark brown / shiny black | Light brown with two light brown bands across wings |
| Habitat | Kitchens, bathrooms, food premises | Cellars, drains, basements, around bins | Warmer rooms, walls, ceiling voids, electronics |
| Temperature preference | Warm and humid (kitchens) | Cooler, damper conditions | Hot and dry (above 25 °C) |
| Eggs per case | 30-40 nymphs | 14-16 nymphs | 10-18 nymphs |
| Public health risk | High - main UK food premises pest | Moderate - sewer associations | Moderate - spreads to higher rooms |
The Three UK Cockroaches
German Cockroach (Blattella germanica)
The most common cockroach in UK homes and businesses, and the species most pest controllers spend their time dealing with.
- Size: 10-15mm long
- Colour: light brown to tan with two distinct dark stripes running down the back of the pronotum (the area just behind the head)
- Habitat: kitchens, bathrooms, restaurants, food premises - anywhere warm with food and water
- Behaviour: rapid breeding (a female can produce 4-6 egg cases, each with 30-40 nymphs), strongly resistant to many DIY insecticides
Oriental Cockroach (Blatta orientalis)
Larger and darker than the German cockroach. Less common in homes but a frequent commercial pest.
- Size: 20-30mm long
- Colour: very dark brown or shiny black
- Habitat: cooler, damper spaces - cellars, drains, basements, around outdoor bins, sewers
- Behaviour: slower than German cockroaches, can survive in cooler conditions, often enter buildings through drain pipework
Brown-Banded Cockroach (Supella longipalpa)
Less common than the German or Oriental but increasingly seen in centrally heated buildings.
- Size: 10-15mm long
- Colour: light brown with two distinct light brown bands across the wings (hence the name)
- Habitat: warm, dry areas - high up on walls, behind picture frames, in electronics, ceiling voids
- Behaviour: prefers higher temperatures (above 25 °C) than other species, can be harder to spot because it doesn’t congregate around water
Signs You Have Cockroaches
You will usually find evidence before you see a live cockroach (they are nocturnal).
- Droppings: small dark specks that look like ground coffee or pepper, found in cupboards, behind appliances, in drawers
- Egg cases (oothecae): small dark capsules, often glued to the underside of surfaces
- Smell: a distinctive musty, oily odour in heavy infestations
- Shed skins: pale cockroach-shaped husks in hidden corners
- Grease marks: dark streaks along walls and skirting boards where cockroaches travel
Why DIY Treatment Almost Always Fails
Cockroaches are remarkably hard to eradicate without professional treatment.
- Hidden eggs: oothecae are heavily armoured. Sprays kill adults but leave eggs intact. New nymphs emerge weeks later and the cycle repeats.
- Chemical resistance: German cockroaches in particular have evolved resistance to common consumer insecticides.
- Hidden harbourage: they shelter deep in walls, behind electrics and inside appliance motors - places sprays and traps don’t reach.
- Squashing spreads them: crushing a female with an attached ootheca can release viable eggs onto shoes and tools, spreading the infestation.
What to Do Next
For an active cockroach problem, professional treatment is essentially the only reliable route. Our cockroach control service combines professional-strength gel baits, residual sprays at harbourage points, and growth regulators that disrupt breeding.
For severe infestations - particularly in commercial food premises - heat treatment kills all life stages, including eggs, in a single visit.
See our how to get rid of cockroaches guide for more on why DIY methods fall short, or cockroach bites if you think you may have been bitten.
Frequently Asked Questions
Do cockroaches bite humans?
Rarely. Cockroach bites only happen in extreme infestations where food sources are exhausted. The bite is small, red and mildly itchy - usually on hands or face during sleep. If you are being bitten repeatedly, fleas or bed bugs are far more likely culprits.
What attracts cockroaches?
Food residue, moisture and warmth. German cockroaches need water more than food - even leaky pipes or a damp dishcloth keep them going. Oriental cockroaches come in from outside through drains or under doors. Brown-banded cockroaches can survive on dry food scraps in dry warm rooms.
How quickly does a cockroach problem spread?
Fast. A single German cockroach female produces 4-6 egg cases in her lifetime, each with 30-40 nymphs. From egg to reproductive adult takes 60-100 days. An ignored infestation grows from a few visible bugs to hundreds within months.
Why shouldn’t I squash a cockroach?
Females carry their egg case (ootheca) attached to their abdomen. Crushing them releases viable eggs that you then track around on your shoes - spreading the infestation to new rooms. Trap with sticky monitors or vacuum directly, then empty outside.
Can cockroaches survive a nuclear blast?
The popular myth is exaggerated. Cockroaches are more radiation-resistant than humans but not invulnerable. They are however remarkably tough: they can survive a month without food, two weeks without water, and a week without their head (until they dehydrate). Resilience is exactly why professional treatment is needed.