One of my co-workers has a mango tree that possums were destroying-tried everything and nothing worked. Then on a Google search, he found a place in Queensland selling an electronic gadget that emits a high frequency sound that humans can't hear, but animals can-including possums. You do ned a power point to plug into, and you need to aim the beam in the direction you wish to protect, but he says the possums don't go near his tree anymore.
