No, this is not about venomous snakes, sharks, spiders or crocodiles.
In common with a lot of Australian households we have uninvited guests in our house.
They are a protected species, and it is illegal to trap them or harm them. We (SWMBO really) decided that we might as well encourage one family of possums and hope that they would fend off newcomers. After a few years of this family we are quite comfortable to have them living in our roof space and between floors. But we do need to fore warn human visitors about the occasional noisy screeching.