When it comes to toilets, there's a simple directional rule: everything goes downstream. When things move against the tide, then you have problems.
So as Tim Fraser was doing some laundry in his bathroom last Friday night, he became a wee bit disturbed when his toilet started spontaneously gurgling.
"I could see bubbles coming up and I thought 'what the the hell is happening?'" he said, recalling that evening.
Then he caught sight of a grey, furry head with a pair of pointy ears and saucepan eyes emerging on this side of the s-bend.
Moments later there was a half-drowned possum sitting in his Fowler toilet bowl.
"It was like the toilet had given birth," he said.
It's not clear who was more startled, man or marsupial. But Fraser was first to react. He darted to the next room and collected his digital camera.
More at From s-bend to YouTube: a possum's tale
Hat tip to Wagga!