As with all snakes seen near water in the Harris County area, the harmless Blotched Water Snake is often incorrectly referred to as a "water moccasin." This is because of its generally dark coloration and its irritable disposition. When threatened, Blotched Water Snakes will behave like all other local harmless water snakes of the genus Nerodia. They will usually coil up and flatten out their head, making it look arrowhead shaped. However, head shape cannot be used to tell venomous snakes from harmless ones. They will also vibrate their tail, let out large amounts of foul smelling musk which smells like a skunk, and strike out repeatedly at whatever is threatening them. This defensive behavior often causes them to be mistaken for the venomous Western Cottonmouth. Since they are not venomous, though, treatment for the bite of a water snake usually involves no more than soap and water and a bandaid.

Blotched Water Snakes are also very closely related to the Yellowbelly Water Snake, Nerodia erythrogaster flavigaster, which can also be found in our area. In fact, the two will interbreed, producing offspring that are darker than a normal Blotched Water Snake, but still possess the small dark blotches on the back. In either case, you will notice that water snakes do not have the wide, dark "raccoon mask" facial stripe seen on the Western Cottonmouth. This stripe can also be seen from a good distance, making identification easier and less likely to cause the snake to feel threatened.

Blotched Water Snakes are often found in yards when they attempt to find new water sources, especially if the yard is watered on a regular basis. Regular watering also attracts frogs and toads, which are a favored food item for these snakes. With these points in mind, you may want to consider watering the yard slightly less frequently if you do not want to attract these kinds of wildlife into your yard.