It is possible that the grey part of the snake that you saw was in fact white, which would provide a lot more possibilities regarding the type of snake that you saw. It the snake was black and white then these are the possibilities: Eastern Garter Snake, Black Rat Snake, California King Snake as well as others.
Below is some more information on each of these snakes and how to correctly identify them.
Eastern Garter Snake.
This type of snake is usually between 18 and 26 inches in length, however, some exceptional snakes can reach up to 49 inches. The distinguishing mark of the garter snake is that they are dark grey or black with three yellow or white stripes. This snake remains active in the day and at night. Their diet usually includes worms, fish, tadpoles, slugs, toads and frogs. Although, these snakes are commonly found in wetter environments such as ponds or streams, they do not pose any threat to humans.
Black Rat Snake.
This species has a black body with a white chin. After it is born, the snake will darken in color and can sometimes reach a length of four to six feet. As implied by the name, the black rat snake likes to eat rats, mice and other rodents. They can also eat lizards, frogs and young birds, as well as their eggs. If provoked by a human, this shy snake will freeze and is known to bite, although it will not do any real damage.
California King Snake.
This species of snake is rather common to have as a household pet. Its body is either black or dark brown with white or yellow stripes. This species of snake will vibrate its tail, sort of like a rattlesnake, when it is disturbed. If they feel threatened they will also curl into a ball and hiss loudly. The diet of this snake is quite varied, including amphibians, birds, rodents, insects and even other snakes.
Below is some more information on each of these snakes and how to correctly identify them.
Eastern Garter Snake.
This type of snake is usually between 18 and 26 inches in length, however, some exceptional snakes can reach up to 49 inches. The distinguishing mark of the garter snake is that they are dark grey or black with three yellow or white stripes. This snake remains active in the day and at night. Their diet usually includes worms, fish, tadpoles, slugs, toads and frogs. Although, these snakes are commonly found in wetter environments such as ponds or streams, they do not pose any threat to humans.
Black Rat Snake.
This species has a black body with a white chin. After it is born, the snake will darken in color and can sometimes reach a length of four to six feet. As implied by the name, the black rat snake likes to eat rats, mice and other rodents. They can also eat lizards, frogs and young birds, as well as their eggs. If provoked by a human, this shy snake will freeze and is known to bite, although it will not do any real damage.
California King Snake.
This species of snake is rather common to have as a household pet. Its body is either black or dark brown with white or yellow stripes. This species of snake will vibrate its tail, sort of like a rattlesnake, when it is disturbed. If they feel threatened they will also curl into a ball and hiss loudly. The diet of this snake is quite varied, including amphibians, birds, rodents, insects and even other snakes.