Unfortunately that shoots my 80% ID down in flames. I got it wrong! These guys are denizens of the forest – shrubs and Bracken and fallen logs and low grass trees are their favoured haunts. They basically won’t enter open areas, not even grasslands. I am afraid you have a sub-adult Black Rat. Did you take the photo? The tail length is diagnostic. Bush rats are highly insectivorous with a percentage of vegetable matter in their diet. Black Rats are omnivorous, eating what ever is available.
Damn! I was all excited for you until now.
Blue