The are lots of non-poisonous snakes here where I live but we do have one species of rattlesnake. And I have survived a bite from one.

I've run into other rattlers, one in Arizona on a hiking trip. It somehow "jumped" out of the way from my foot as I was walking towards a mountain stream to cool off. I stopped and photographed her and we both went on our way.

I've nearly stepped on a decent sized puff adder on my frist trip to Africa while I was heading to the "ladies" room after killing my eland bull. The snake was perfectly blended in a small shrub I was walking past. I will never forget the sound it made. It never did try and strike, it was just letting me know where I should not put my foot! I was within a linear foot of it's position.