There are two common species of rats located in the Perth area. The Norway rat is the type you will type you will find trying to access your home and sheds. The other type of rat you will find is a roof rat, which are found in the roof voids of many homes.
While Norway rats are obviously more invasive if they gain access to your home or shed, roof rats can cause serious problems, as they like to chew through electrical wiring which can cause electrical issues and even fires.