Letting rats live a little longer by ceasing to poison and trap them proved a killer move by the Bream Head Conservation Trust.
The successful predator removal scheme involved ceasing the regular poison - not laying for a few months so rats lost their wariness about it, letting them breed up in numbers, then hitting them with a ground-laid 1080 bomb.
It was a double whammy because then stoats ate the rats that ate the poison and died too.
The result of the major operation that started in April was very satisfying, according to head ranger Adam Willetts.
"This was a planned and desired outcome from the toxin removal, that rats would be in better numbers to consume 1080 pellets from bait stations and be the delivery vector to stoats via hunting predation, and therefore transfer secondary poisoning," Mr Willetts said in the group's newsletter.