The short-beaked echidna (Tachyglossus aculeatus) is found in pretty much every Australian bio-region, from the cold Aussie Alps, to the arid Outback. So wherever you live, there are almost certainly echidnas in the bush near you. I've seen echidnas nearly every time I've visited the Royal National Park (just south of Sydney), as long as the weather was warm enough. When you're walking through the bush, listen out for their rustling through the undergrowth. They eat mostly termites and ants, but it also other insects.
They usually try digging themselves into the ground if they can't get away in time, and it's a surprisingly effective defense. They're good at gripping the ground with their claws and they can jab outwards with their spines if touched.
Just think: this animal knows how to stay safe and find food wherever it goes. When the weather gets too cold, it just hunkers down somewhere sheltered and goes to sleep. Talk about living the Dream! As with all animals, echidna can teach us a whole lot about bushcraft.
This young echidna hung out with us for a bit, and then decided we weren't trying to eat him, and waddled away into the bush. He (or she) was pretty camera shy, but you can just about see the eyes peering out in this pic below: