But no, it moved. It was walking slowly but purposefully across the patio.
On closer inspection I saw it was another example of the extraordinary stick monster caterpillar thing, that I'd first noticed a few months ago, attempting to cross a busy street in Parramatta. It sticks its head out the front, and drags its heavy cocoon along behind it. Here it is close up.
After the earlier encounter, with the suicidal one, I'd spent quite a while fruitlessly searching the internet for images which might give me a clue as to what it's name was. It's like that with the internet sometimes. It knows everything, but unless you think of the right search words, it can be unexpectedly opaque. I'd been putting in terms like 'mud stick monster', among others. This new sighting spurred me on to try again, and this time there was success.
I think it's a Saunders' Case Moth (Metura elongatus). The caterpillar builds its home, and as it grows it extends it by adding one stick at a time, apparently by retreating into its case, and piercing it from the inside and threading the new stick in at just the right place. Each new insertion can take an hour or two. There are leaf moths too, and my specimen had a couple of leaves mixed in with the sticks. Maybe he'd had a slight identity crisis.
More about it, and pictures of the beautiful moth that emerges after a year or two at: http://lepidoptera.butterflyhouse.com.au/psyc/elong.html
I've also solved the mystery of the Thing That Hangs at the Garage Back Door. It's been hanging there for years, since we moved in in fact. It seems to be a used Saunders' Case Moth case.
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