Teacher Linda Ireland said the students had written stories from the perspective of the fruit fly and she had been impressed and thought the ministry would be interested.
So impressed were ministry officials that yesterday's trip was organised as a special treat.
Before retiring Griff featured on the television programme Dog Squad with Ms Moore.
During his career Griff sniffed nearly 500,000 incoming passengers and snapped 6566 people carrying plant or food matter.
But old habits die hard and from the moment Griff trotted into the classroom he couldn't stop sniffing and the children couldn't help but try to pat him.
An apple in the camera bag of Northern Advocate photographer Michael Cunningham was quickly detected and became lunch for the canine sleuth.
Ms Moore was quick to point out that working dogs were not allowed such luxuries and anything they did find was quickly recovered and handed over for destruction.
On finding out Griff was 12 years old one of the students exclaimed: "He's way older than me."
During a question-and-answer session it was explained the detector dogs were trained specifically to sniff out plant and animal matter and there were about 35 operational beagles based around airports in New Zealand.
That prompted questions from the children including. "Do they sniff for lollies?" and, "Can they smell money?"
While there was an MPI breeding programme, the ministry sometimes were given dogs by members of the public.
One pupil said he didn't have a dog but he had two rabbits that he generously offered for training.
And on the topic of training one student asked if cats could be trained to sniff.
Ms Moore now features on television shows with current detector beagle Watchman.