Cockroaches are a common household pest in Aotearoa New Zealand. They thrive in unhealthy environments and can transmit a number of diseases. Most native cockroaches are not dangerous, and they are very important to our environment.

Health risks from cockroaches

Cockroaches can spread diseases like:

  • dysentery (an infection and inflammation of the intestines)
  • salmonella (an infection that causes diarrhoea, fever and stomach pains)
  • diarrhoea (runny poos).

Their eating habits also expose people to dangerous diseases. Cockroaches can eat a range of foods, from faecal matter to fresh food intended for people to eat. If cockroaches contaminate your food or the surfaces you use, you could get sick.

How to prevent a cockroach infestation

The biggest cockroach pests in Aotearoa New Zealand are the American cockroach, and the German cockroach. If you have cockroaches, but are not sure what type, visit the Manaaki Whenua Landcare Research. They have pictures and more information about these.

How to reduce the chance of a cockroach infestation

You can reduce your chances of a cockroach infestation by:

  • filling cracks in walls and foundations
  • keeping living areas dry and clean
  • disposing of rubbish
  • removing human waste and food waste from the home quickly and efficiently.

If you already have cockroaches

If you already have cockroaches, you might need to:

  • set baited traps
  • apply an insecticide to the area.

Insecticides work best when applied to areas where:

  • cockroaches hide during the day
  • they pass through at night time.

It is important to keep your home clean and dry to stop you from getting cockroaches in the first place.

More information about pests and infestations is on the Tenancy Services website.

Pests and infestations — Tenancy Services (external link)

Where cockroaches live

Cockroaches prefer damp, dark places. They are often found inside walls, behind household appliances, and in cupboards.

Cockroaches thrive in warm and damp conditions. They will dehydrate if the environment is too dry. But, they can survive in extreme conditions for short periods of time. Cockroaches can survive months without food and up to 4 weeks without water. This makes them very difficult to get rid of.

The lifecycle of cockroaches

Cockroaches go through 3 stages of development — egg, nymph, and adult.

The egg hatches into a nymph, which looks similar to the adult cockroach. The nymph then goes through a series of moults before developing into a fully reproductive adult cockroach.

It can take anywhere between a few weeks to a year to complete the cycle.

Female cockroaches are able to lay hundreds of eggs in their lifetime.

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