Water snake identification: water moccasin or just a nuisance?

With owning a pond comes the inevitable occurrence of encountering all kinds of wildlife. Most will be harmless creatures looking for water, but you will no doubt come across a snake or two. While snakes undoubtedly have an undesirable reputation, they can be beneficial creatures to be around. They control populations of rodents and other pests that might otherwise get into your home. However, it is important to know the difference between a harmless water snake and a poisonous water moccasin, as a false identification can lead to a devastating result. Unless you can safely tell the difference between harmless and poisonous snakes, it is best to always treat all snakes as if they were poisonous.

There are several key differences that can help identify which of these snakes you may encounter. The most notable difference is the shape of the head. The head of a water snake will be thin and flow smoothly towards the neck, while the head of a water moccasin is much more blocked and the neck much narrower when it meets the head. Also, water moccasins are commonly known as “cottonmouth” because the inside of the mouth is white, which they often show as a sign of defense.

The second difference would be the shape of the body. Water snakes tend to have a long, lean body type, while water moccasins have a short, stocky build. However, this alone should not be used as a key identifier as the body shape can vary from snake to snake. Also, in some cases, the water moccasin may be a lighter color. However, both snakes can range from brown to black, so again, color should not be used alone either to make a conclusion as to the identity of the snake.

The following is the shape of the pupil. If you are close enough to see the snake’s pupil (and we suggest avoiding that proximity), water snakes have a round pupil and water moccasins have a vertical pupil.

In terms of the behavior of both snakes, the Moccasin in general appears much more aggressive with a predominant head, plump body, and vertical pupil. Water moccasin bites are known to cause serious symptoms such as bleeding, numbness of the limbs, skin discoloration, and even death. Therefore, as mentioned above, unless you can safely, easily and properly identify a snake, it is best to treat it as a poisonous snake to avoid any danger.