AgResearch used to find possums reasonably easy to obtain.
But success in ridding the country of the pest has created a shortage, and AgResearch is asking for the public's help.
In a touch of irony, much of the research was to find toxins or other methods to control possum numbers, which already had dropped from an estimated 70 million to half that.
AgResearch Invermay scientist Dr Bernie McLeod said a good night's trapping used to return seven to 10 live animals from 20 traps, but possum numbers had been reduced.
AgResearch would provide homeowners with a box trap and would collect caught possums.
About five possums a week could be needed, perhaps more during busy periods.
AgResearch technician Euan Thompson said more possums had to be caught than were strictly needed, to provide scientists with animals of the right age, size and gender.
About 80 possums are housed at Invermay, which has space for up to 150.
A newly built storage and handling complex will be able to house another 200.
Dr McLeod said all research and handling of the animals was approved by animal ethics committees at Invermay and the University of Otago.
Researchers hoped to control the possum population with possum-specific toxins and a way to interrupt reproduction.
Possums spread bovine tuberculosis, which infects cattle and deer and could threaten New Zealand's exports if left unchecked.
Possums also have a voracious appetite for native flora and fauna.
