My folks bought a small retirement farm in New Zealand in the 1980’s. I visited each summer for a few years when we had our long holiday recess from uni.
They lived in the Northlands dairy district north of Auckland which had plenty of Brown Rats or Norway Rats.

Each evening they would enter into the house through very sneaky ways. I think they may even have had a spare set of house keys. I woke one night with one of them sitting on my chest. Very inquisitive little creatures.

I wanted to double check though if it was a Brown Rat or maybe it was a possum as they sometimes came inside. It was dark as I fumbled around to find the light switch and whatever it was had scuttled away very quickly. So, like jon14 suggested I set up a video camera (VHS, no less) and put out some nibbles and some water in the middle of an unfolded New Zealand Herald broadsheet.

The rat that I caught on video was some size. From nose to tail it was longer than half the broadsheet. Yikes!

Brown Rat