Since the Garden of Eden, snakes have been a source of contention for humans. Though Eve lost her battle with the serpent, scientists have since learned that snakes are not only prolific, but useful, and most snakes are not poisonous. Snakes can be found everywhere in the world except for New Zealand, Ireland, and a few other islands. Out of the approximately 2,700 species of snakes on the planet, less than 600 are poisonous.

The Colubridae family of snakes makes up about two-thirds of all snakes in the world, most of which are not poisonous. Garter snakes are a common non-poisonous Colubrid snake that live both in water and on dry land. Garter snakes are found in every state in North America, Canada, and as far south as Central America. They eat mainly fish worms, and frogs, and their females bear live young.

Other non-poisonous snakes include black snakes, racers, king snakes and rat snakes. Black snakes can be speedy and aggressive, quick to bite, but not poisonous. They often have a constricting ability and are helpful to have around to control garden and household pests, such as mice. The king snake is a large, impressive snake that feeds on birds, rodents, and other small creatures. It is famous for being immune to the bite of a rattlesnake or copperhead.

Boas and pythons come from the family Boidae which includes some of the largest snakes in the world. Boas and pythons are known for squeezing their prey until it suffocates and then swallowing it whole. Found mainly from Mexico to South America, these large snakes often lie in wait next to watering sources and then attack animals that come to drink.

Poisonous snakes are the ones we humans worry about the most. Poisonous snakes, including the copperhead, water moccasin, and rattlesnake, belong to the pit viper family. Pit vipers have fangs that lie back against the roof of their mouths until they strike. They are named for the small pits located just behind their nostrils; these pits alert them to warm blooded creatures that might make a good meal.

Regular vipers are found mostly in Eurasia and Africa, and are similar to pit vipers, but often have geometric patterns on their skin. Coral snakes, asps, adders, and certain cobras belong to the viper family. Sea snakes are also a poisonous snake that can grow to surprising lengths; they reside in the tropical seas of the world.