MY VERSION OF STOP, CRAP, AND ROLL!
There are only 4 species of poisonous snakes in North America; cottonmouth water moccasin, rattlesnake, copperhead and coral snake. Learn to identify these snakes from photos, and you can safely assume that all other snakes you see in North America are non-poisonous.
Absolutely. They live in a world of eat or be eaten. They take one look at us and “think”, “I can’t eat this thing, but it’s big enough to eat me”. Consequently, they are very much afraid of us.
Source: http://www.wikihow.com/Identify-a-Venomous-Snake, Herrick, Jack et all, Internet, April 27, 2011