We have found several... and they have all been huge! They obviously thrive in those conditions... maybe the smells attract a good supply of flies!
My youngest son had a close encounter with one and now won't go near a long drop (or any toilet for that matter) without checking for 'nasty spiders'
Here's a except from a previous trip...
"1st action for the day was a toilet stop for Corey. As Mum was checking he'd wiped his bum properly (it's a learning process!) he remarked there was a "poisonous spider under the seat". Glenda checked and there was a Redback spider under the bowl at the front. He must have been eye-balling it from a few centimetres away! Glenda disposed of it with a stick. As the nearest loo was occupied, I went to the other nearby for my morning twinkle. At the back of this one was the biggest Redback I've ever seen, the body of it was over a centimetre long. I thought of attacking it with the dunny brush but decided that might just make it angry so went looking for a suitable stick. Glenda saw me walking around and guessed I'd found another. Later that evening, Glenda found another at the back of the 1st toilet. Any future bush loo visits will be preceded with a spider check. "
On our trip to the Flinders Ranges recently we found a bunch more!