All You Need To Know About Australian Cockroaches

Learn How To Identify And Avoid These Pesky Pests

Guide To Australian Cockroaches

Cockroaches are tiny scavenging insects that have been around since the time of the dinosaurs. Currently, there are approximately 4,000 species of cockroaches on the planet, with about 450 cockroach species in Australia. The most common variants in the country that invade homes and businesses are Australian cockroaches, American cockroaches and German cockroaches. Today, Scott Dixon, a professional from  Pro Pest Control Gold Coast has shared how to identify these pests and stop them from getting into your property.

When Are They Most Active?

Australian cockroaches are most active in warm, humid environments and, like their relative species, keep themselves hidden during the day. They´re nocturnal creatures and only come out at night to search for food. This means that you may not realise you have an infestation in your home unless you´re up late and turn on the lights.

What Are The Dangers Of Australian Cockroaches?

Australian cockroaches (Periplaneta australasiae) and other roach species are considered dangerous as allergen triggers and asthma sources. According to the Centres for Disease Control and Prevention (CDC) in the United States, they don´t bite. However, they may scratch, and they carry bacteria.

Australian cockroaches pick up bacteria from various sources such as rubbish and the faeces they eat. They can leave these all over your food and countertops, including Salmonella, a bacteria that causes diarrhoea, fever and stomach cramps.

Species Overview

Here´s a quick guide to some of the most common cockroach species in Australia.

Australian Cockroach – Periplaneta australasiae

A common species of tropical cockroach that despite its name is not native to Australia.

Appearance: Reddish brown to dark brown with yellow markings on the top of the head and front edge of each wing.

Size: Typical length is 23 to 35 millimetres.

Habitat: An outdoor species that live in colonies in areas with relatively mild winters and high humidity. Indoors you’ll find them in bathrooms, kitchens and other places close to water sources.

Life cycle: Nymphs take approximately 6 to 12 months to grow into adults. The average lifespan of an adult is four to six months.

American Cockroach – Periplaneta americana

One of the largest cockroach species that can infest homes.

Appearance: Reddish-brown with a yellowish figure eight pattern on the head.

Size: 35 to 41 millimetres in length, on average.

Habitat: Live on trees but prefer dark, humid environments. They´re often found in basements, kitchens, bathrooms and roof voids in the home.

Life cycle: Eggs take one to two months to hatch. Nymphs develop into adults in six months to one year.

Australian Cockroaches

Oriental Cockroach – Blatta orientalis

Despite its name, the oriental cockroach is believed to be of African origin. They are also known as water bugs because they prefer damp areas. Oriental cockroaches run. They do not fly.

Appearance: Smooth, shiny bodies that have a black to a dark reddish-brown colour.

Size: 20 to 25 millimetres long.

Habitat: Cool, damp and dark areas such as basements and drains.

Life cycle: Eggs hatch after two months and it takes a further 6 to 8 months for a nymph to grow into an adult.

Smoky Brown Cockroach – Periplaneta fuliginosa

Pests that enter homes and contaminate food with their excrement and saliva. Are very good flyers.

Appearance: Dark, glossy brown or mahogany colour. Males and females have wings that extend past their abdomens. Antennae that are as long or longer than the entire body. Enter buildings at night.

Size: 30 to 35 millimetres in length.

Habitat: Live in and around wooded areas in regions with high humidity.

Life cycle: Nymphs develop into adults in 6 to 12 months.

Brown-Banded Cockroach – Supella longipalpa

Small cockroach species that can spend their entire lives indoors.

Appearance: These invasive cockroaches get their name from the two light brown bands across their darkish brown bodies.

Size: 10 to 15 millimetres in length, making them one of the smallest cockroach species.

Habitat: Prefer warm, humid environments. In homes, brown-banded cockroaches can be found in bathrooms, kitchen cupboards, attics and ceilings.

Life cycle: Brown-banded cockroaches live for around 200 days. Females will lay an average of 14 egg capsules during their lives. Each one contains 10 to 18 eggs.

German Cockroach – Blatella germanica

Small, aggressive cockroach species. Although possessing wings, they prefer to run rather than fly.

Appearance: Light brown or tan colouration with two black stripes behind the head.

Size: 12 to 15 millimetres in length.

Habitat: Mostly found indoors in warmer and more humid parts of a building, such as kitchens and bathrooms.

Life cycle:  From egg to fully grown adult can take six weeks to six months. Adults typically live for between 100 and 200 days.

German Cockroaches

How to Identify an Australian Cockroach?

The best way to identify Australian cockroaches is to first look at their size. They tend to be bigger than other species, reaching 23 to 35 millimetres in length. Other distinguishing features include the yellow markings on their head and the front edges of each wing. To distinguish a male from a female Australian cockroach, look at their backsides. A male has a pair of tiny appendages called styli that are used during mating.

How To Control Australian Cockroaches

Here are a few handy tips for effective cockroach control in your home:

  • Keep food in sealed containers.
  • Ensure your home is clean, especially the kitchen.
  • Don’t leave pet food out overnight.
  • Rinse food waste packaging before placing in recycle bins.
  • Clean under, inside and behind (if possible) appliances regularly.
  • Remove unnecessary containers of water.
  • Repair leak pipes and taps.
  • Cover night-time drinking water or have a sealed bottle by your bed.
  • Keep compost bins away from your home.
  • Seal potential cockroach entry points such as cracks and gaps in walls.
  • Cover vents with a fine mesh, if possible.


Remember, even though they may look harmless, Australian cockroaches can put your health at risk.

Once an infestation takes hold in a home, it can be challenging to eliminate. Therefore, call professional pest controllers who will have the correct treatments, approaches and knowledge to get the job done.