Professional exterminators

Pest exterminator Jon Thomson (right) backed his car out of the driveway before fumigating the house: "The infestation was so bad that it was the only way to avoid being swamped when the cockroaches fled."

Jon has worked for Rentokil for 21 years and has a swath of horror stories to tell. But it's the cockroaches that stick in his mind: "There were about 30 cockroaches under the baby's pillow in the crib. It was pretty disturbing."

Hiring a professional

You'll need to call a professional exterminator to deal with established pest infestations. The bonus is that you can go grab a coffee while someone else deals with the creepy crawlies.

There are many pest extermination companies in the yellow pages - and there's a trade association as well. Members of the Pest Management Association of New Zealand have technical training in pest eradication. You'll find a nationwide list of registered technicians and companies on the association's website: www.pmanz.co.nz.

The association may also be able to help you if you're not satisfied with work carried out by one of its registered technicians.

Approved handlers

Pest exterminators working with substances that are toxic to humans or the environment must be approved handlers under the Hazardous Substances and New Organisms (HSNO) Act 1996. They apply to become handlers through the Environment Risk Management Authority. HSNO-approved handlers have demonstrated the necessary knowledge, safety skills and practical experience to handle potent pesticides.

Ask a pest exterminator whether or not they're a qualified handler before hiring them.