Signs of Cockroaches

  • Cockroach droppings;
  • Smear marks;
  • Cockroach eggs;
  • Shed skin;
  • Damage to property;
  • Unusual odor;
  • Live cockroaches.

The German cockroach (Blattella germanica) is a small species of cockroach, typically about 1.1 to 1.6 cm (0.43 to 0.63 in) long.  Of the few species of cockroaches that are domestic pests, it probably is the most widely troublesome example.

The German cockroach occurs widely in human buildings but is particularly associated with restaurants, food processing facilities, hotels, and institutional establishments such as nursing homes. German cockroaches are omnivorous scavengers. They are attracted particularly to meats, starches, sugars, and fatty foods.

The German cockroach reproduces faster than any other residential cockroach, growing from egg to reproductive adult in roughly 50 – 60 days.

The German cockroach is very successful at establishing an ecological niche in buildings and is resilient in the face of many pest-control measures. Reasons include:


  • lack of natural predators in a human habitat
  • prolific reproduction
  • short reproductive cycle
  • the ability to hide in very small refuges
  • sexual maturity attained within several weeks, and
  • adaptation and resistance to some chemical pesticides


To be effective, control measures must be comprehensive, sustained, and systematic; survival of just a few eggs is quite enough to regenerate a nearly exterminated pest population within a few generations, and recolonization from surrounding populations often is very rapid, too. 

Another problem in controlling German cockroaches is the nature of their population behavior.

Though they are not social and practice no organized maternal care, females carry oothecae of 18-50 eggs (average about 32) during incubation until just before hatching, instead of dropping them as most other species of cockroaches do. This protects the eggs from certain classes of predation. 

Without proper pest control, your property can become an ideal breeding ground for cockroaches.

This common pest in Australian homes can enter your property through the tiniest cracks and crevices as well as through pipes and plumbing. No one wants to cockroaches in their property.

Here are ways you can prevent a cockroach infestation.

The Oriental Cockroach

The oriental cockroach also is known as the waterbug or black beetle, is a large species of cockroach, adult males being 18–29 mm (0.71–1.14 in), and adult females being 20–27 mm (0.79–1.06 in). It is dark brown or black in color and has a glossy body.

The female has a somewhat different appearance from the male, appearing to be wingless at a casual glance, but is brachypterous, having non-functional wings just below her head. She has a wider body than the male.

The male has long wings, which cover two-thirds of the abdomen and are brown in color, and has a narrower body. Both sexes are flightless

Signs of cockroaches are their “egg cases”. The blackish-brown oothecae of the oriental cockroach are 10–12 mm (0.39–0.47 in) long, with indistinct egg compartments housing 16–18 eggs.

These oothecae are formed a day after mating, and typically deposited a day or two after formation, though can be deposited up to 7 days later, typically in a sheltered area or attached to a substrate by oral secretion.

They are initially a yellow-white, turning reddish- then blackish-brown. They lose viability at temperatures below 0 °C (32 °F). They hatch on their own in about 42 days at 29.5 °C (85.1 °F) and 81 days at 21 °C (70 °F).

Oriental cockroaches can be harder to get rid of than other roaches. Although adults can be fairly easily killed by the application of residual insecticide, the insecticides can get washed away, and two months later females can hatch new nymphs.


Call a professional to help you if your problem persists…

The Dusky Cockroach


Dusky Cockroach | Rentokil Pest Control Australia
  • Adult males 3/8″-7/16″.
  • Adult females 1/4″-5/16″.
  • Body dark grey-brown except for dark male pronotum and female dark brown abdomen.


  • Egg cases, known as oothecae are produced and carried by the female for one or two days between June and September.
  • The oothecae overwinter on the ground and the nymphs hatch in the spring.
  • The nymphs hibernate during the late stages of development to become adults in July.
  • The adults die from September to October.


  • The dusky cockroach is mainly ground-dwelling and favors scrub, grassland and woodland habitats.
  • Males only fly in warm weather.

How can you prevent a cockroach infestation in your home?


Eliminate food sources.

Cockroaches are scavengers. They scour your kitchen for food at night to survive. To discourage this, you need to eliminate their food source. Store food in tightly sealed containers or plastic bags.

Do not leave food sitting unattended on your kitchen counters. Always empty the sink and clean the dishes every night.

Clean your kitchen appliances especially your fridge, microwave ovens, and toasters for crumbs and other food particles. Kitchen cabinets and the area under your sink can also have food spills.

Always clean your kitchen counter with disinfectant to deter them from walking over them and eliminate their pheromones. Finally, use a tightly lidded trash can and empty it every night.

Eliminate entry points and hiding spots.

As we’ve mentioned, cockroaches can enter your home through cracks and plumbing.

As for their hiding places, cockroaches prefer tight cracks and dark empty spaces to hide during the day.

Eliminating these can help you prevent a cockroach infestation. Seal cracks and crevices as well as holes in your roofs or crawlspaces. Avoid clutter especially in your cupboards and your floors.

Doors and windows should fit within their frame to avoid cockroach entry. Varnish wooden shelves and cabinets to seal them.

Consult cockroach pest control experts.

If you see signs of infestation or would like to prevent it from happening in the first places, the best step you can take is to talk to cockroach pest control experts.

These experts have extensive knowledge of the behaviour of each species of cockroach that plagues your property.

They also know the best way on how to deal with them, including the proper pest control treatment to use against the specific type of roach you are dealing with.

Request a Free Quotation Today!

Buy DIY Products Online

Certified Pest Control Operators


Customer Satisfaction

Some of our clients