Hi Sciencegal, thanks for the sighting. I cant tell for sure from a head on photo what this is, but I suspect Rattus rattus, Black Rat. In decades of reported Smoky Mice, Broad-toothed Mice, Bush Rats, Antechinus and Bandicoots in Canberra Suburbs, so far every one has turned out to be a Black Rat (although some householders absolutely refuse to accept that) so I'm still looking. A photo showing the tail length in relation to body length, or a side view of the head and ears, or the pads under the feet would be easier to diagnose. A bush rats tail is shorter than its head-body when bent forward unnaturally. And its ears do not reach past the middle of its eye when folded forward.