Although king snakes and rattlesnakes are both common inhabitants of the southwest United States, these two species of snakes are very different. King snakes, although some species may superficially resemble coral snakes, are not venomous and are most known for feeding on other snakes. The rattlesnake is one of only four species of venomous snakes in the United States and can be deadly to humans.
King snakes usually grow to two to four feet long and assume a variety of colors and skin patterns. While they are often associated with desert regions, king snakes actually have the largest geographical range of any land snake. They are found from southern Canada all the way to northern South America. King snakes hunt during the day and use their powerful bodies to constrict and suffocate prey. Because king snakes have an enzyme that breaks down poison from venomous snakes, they frequently prey on rattlesnakes, coral snakes and cottonmouths.
Rattlesnakes, on the other hand, are concentrated mostly in the southwest desert regions of the United States and can grow to be anywhere from two to six feet in length. Their skin is deeply patterned for camouflage. They are also highly venomous and use their fangs to inject their prey with immobilizing venom. They generally hunt lizards and rodents and swallow their prey whole. The rattlesnake's most known predator, because of its immunity to the rattlesnake venom, is the king snake.