Kiwi man Owen Stobart is the country's go-to when it comes to exterminating rodents.
"The more I deal with rats, the more I respect them. Unfortunately, my job is to take them out," Mr Stobart says.
Mr Stobart attended Rat Academy in the US, which is run by pest control legend Dr Bobby Corrigan, the only person with a PhD in urban rat control.
"Rat Academy is a course which essentially focuses purely on urban rat control … and he [Dr Bobby Corrigan] shows you lots of different scenarios and gives you the correct solution, according to his research and studies.
"Bobby Corrigan told us to ignore rat poo and look for the sebum trails because the sebum trails tell you where the rats are going."
Sebum is the mark of oil from the sebaceous glands from the rat's fur and are like "rat traffic lights".
"It shows you an area the rats trust, and they frequent on a regular basis."
Mr Stobart says the rat population is linked to the human population which suggests that rats will be more of a problem in the future.
"The more people we have, the higher the number of rats."
A highlight of the job has been exterminating 10,000 rats in Auckland.
"It was considered to be one of the worst rat jobs in the world. Luckily that's sorted now."