How to live with possums
(1) Block access to your roof by:
*placing collars made from sheet iron, 60 cm wide and 60 cm above the ground, around the trunks of all trees giving access to the roof. Collars may also be used to keep possums out of fruit trees.
*lopping branches which lead to the roof.
(2) Make or buy a nest box and install it in your garden as an alternate den site for the possum. Possums are territorial. If one adopts the nest box, it is likely to keep others away from your garden (and roof).
(3) Block all known entrance points once possums have left your roof, and wipe around entrance points with household bleach to remove possum scent.
(4) Ornamental plants or fruit being eaten by possum may be protected by placing blood and bone fertilizer around the base of plants or by making a solution of hot english mustard (mustard powder and water) which can be sprayed on the affected fruits or foliage.
Trapping and removal of possum is not recommended
*it seldom solves the problem, since another possum usually moves in to occupy the vacated territory and den site in your roof.
*released possums may displace other wildlife, such as owls or gliders, from hollows.
*released possums are at high risk of being killed by cars, foxes or dogs, or battle with the local possums for a den site. Possums are protected, like all other native animals under the Wildlife Act 1975. They must not be harmed in any way.
More information in the link below: