People presume that snake are not present in some areas because they, having lived there for many many years, have never seen one.
It is assume by many of my neighbours that every red belly in our area must have escaped from me or that I release them there.
One bloke told me how he had played on the line as a kid and never seen anything. No bluetongues, no water skinks, no frogs and no snakes.
I would love to take the credit but its not mine to do so.
ps. wasn't there recently a snake that used toxins from its prey to render itself poisonous.