Yep we have them here too and it's certainly not tropical. Not a big deal ATM as it's so dry but during cool damp weather, the bush here is full of em.
When they haven't eaten for a while, they are skinny like an earthworm and they hang off the end of leaves in the scrub and latch onto you as you push through (well more often wallabies). At this stage, they are so skinny, that they can crawl through the eyelets on your boots, through the weave of your socks etc where they get stuck in. First thing you know is that your boots are full of slushy stuff, feels like water but when you take em off, they are soaked in blood and there's a HUUUGE big black leech (6 inches long and an inch across), groping around blindly up your ankle, trying to crawl away to digest his meal.
Usual way to remove em is with salt or a lighted cigarette held close.
When I was in the Army Reserve here, we used to get covered in em when in our Training Area inland of the East Coast. The worst thing is that the blood doesn't coagulate, so you ooze blood for hours and it just makes a horrible mess everywhere. It's not at all painful but I remember lying on the edge of a clearing one cold wet night, for hours on an ambush, imagining I could feel them crawling on the back of my neck. Worst part was that after we'd sprung the ambush some hours later, I hadn't imagined it and I had half a dozen on me, including in my hair, feeding through my scalp and right down my back under my shirt. When I got home from that trip, all three spare uniforms were stiff with dried blood.
I've seen people with em up their noses, even one guy who found one latched on under his foreskin. He wasn't too keen on the idea of the lit ciggy either.
There'a an amusing account of a bit of a leech attack in here
Tassy Highlands Trip
There are some great photos on here if you care to look too.
Richard M