Roof walking

As I have mentioned over the years, our house has regular visits by possums and (unfortunately) rats:  the latter always start turning up in the ceiling in autumn when the summer oven like temperatures in the roof space start cooling.   We hear them, I go up into the ceiling and lay baits and look for dead bodies.  (Fortunately, they mostly seem to die elsewhere.) 

As for possums - they are not infrequently seen on the balcony rail, or heard scurrying along the lower part of the roof (which, conveniently for them, comes close to a very large tree in which you can also hear them rustling at night.)

In the morning, sometimes we have had birds hopping on the roof, too.

So I've heard animals on or in the roof, a lot.

But lately, including early this morning, there is something on the roof which makes a sound which is oddly like footsteps.  It does not have a scurrying quality at all, it sounds like the slowish thump, thump, thump of a person walking carefully on a roof.

I mentioned it at lunch, and my daughter says she has heard it in the evening.  I've only heard it later at night, or very early in the morning.

I'm a bit puzzled about what Australian  animal can make a roof noise like that.  Googling the topic I see from this handy American guide to things in the attic that raccoons can make a walking sound.
The things is, based on past experience, I am a bit skeptical that possums, even large ones, move in such a way that they can sound like footsteps.   Can't see what else it could be, though.  A very large  cat is not out of the question, I suppose, but we will have to see.

The incident has put me a bit in mind of the "devil's footprints" story from 19th century Devon, minus the snow, of course.     I can imagine people in, say, the midst of a witch panic, being wound up over the sounds of (what they think is) footsteps on a roof.