Actually, I have no idea what the statistical outcome of sitting still would be - good prehistoric statistics are hard to come by. Modern medicine will tell you that the one thing you do not want to do is start running... With snake bites, because of the large number of dry bites, small amounts of injected venom, etc. many spurious remedies for snakebite venom have come into popular folklore (like whiskey as a cure, or the prevalence of "cut and suck" for many years).

Snakebites are a relatively minor problem in the outdoors. You are far more likely to get into trouble from a fall, various forms of drowning, or from weather extremes of heat and cold. This is what actually kills and injures people in the outdoors, not animals.

Learn and practice good preventive techniques. Do not stick your hands into crevices or into places where you cannot see clearly. Walk cautiously through brush and make a lot of noise. Be alert, not just for critters, but for all the other things out there.