A pointed tail is not an adequate way to determine if a snake is venomous, according to Michigan Wildlife. Venomous snakes within the United States include pit vipers, such as the copperhead, rattlesnake, cottonmouth (water moccasin) and the coral snake.
Pit vipers are distinguishable by the pair of infrared-sensing organs, or pits, located between the eye and nostril on each side of the head. These organs detect the body heat of mammals and provide the snake with additional sensory information. Coral snakes belong to the elapid family and are identifiable by their red, yellow/white and black bands. Milk snakes are a nonvenomous species that share the same coloring but in a different arrangement.