Cottonmouths and water snakes can be found in similar areas and environments—so how do you tell them apart? Keep reading to learn about their key similarities and differences.

The cottonmouth snake

Cottonmouth snakes are also called water moccasins. Cottonmouth snakes are semi-aquatic snakes. That means that they live in aquatic environments, meaning they are found in or around water, though they can live on land. Cottonmouths are most frequently found in the southeastern United State s. They prefer to be around swamps, rivers, and wetlands with heavy vegetation. For those familiar with snakes, seeing a cottonmouth would probably be alarming—and that’s because cottonmouths have a venom that is dangerous to humans. In fact, the cottonmouth is the most aquatic of the venomous snakes in North America. W hen threatened, a cottonmouth will often coil its body and open its mouth in warning. The inside of the Cottonmouth’s mouth is a light whitish color resembling cotton—hence their name.

Now that you know a little bit about the cottonmouth snake, its habitat, and its behaviors, let’s look at some of its physical traits. It’s extremely important to note that you should not try and get close to a snake to identify it; bites can happen when snakes feel threatened or when people attempt to handle them. Listed below are several common physical attributes that can be used to tell if the snake you see is in fact a cottonmouth.

  • Size: On average, adult cottonmouth snakes can grow to be up to around 2 -3 feet in length.
  • Color and pattern: The color and pattern of cottonmouth snakes can vary. They may have broad crossbands, which darken with age. Young cottonmouths are almost always strongly patterned with crossbands and have yellow tails. As they grow older, the crossbands may darken almost completely so that cottonmouths may appear to be fully brown or black.
  • Distinguishing characteristics: Cottonmouths have large, triangular heads that are both flat and broad. The top of their eyes are covered with scales so they are not visible when viewed from above.

It’s also worth noting that cottonmouth snakes are pit vipers, so they have the telltale facial pit that they use to sense temperature and which can help detect predators or even prey. Facial pits a re hard to see and therefore, you should treat all snakes as if they are venomous and keep your distance.

The water snake and its differences and similarities to the cottonmouth

When it comes to the cottonmouth snake vs. the water snake, the most similar characteristic is that they are both snakes found in and around water. The main difference between the cottonmouth and the water snake is that the latter is nonvenomous. Though the water snake does resemble the cottonmouth, it’s not harmful to humans. Even if the cottonmouth and water snake seem similar in appearance, there are a few key differences to note. As mentioned previously, you should not get close enough for a snake to strike you, so while these differences are interesting to know, it’s better to be safe and keep your distance.

  • Eyes: You can see the eyes of the water snake from above, unlike the cottonmouth’s eyes. Additionally, the pupil of the water snake is round compared to the cat-like slit of the cottonmouth snake.
  • Head: The water snake has a much rounder head than the cottonmouth, which as mentioned has quite a wide, broad and triangular head.
  • Body shape: Water snakes have a more slender appearance than cottonmouths, which are thicker in size.
  • Behavior when threatened: Cottonmouths will often stand their ground, while water snakes will likely flee
If you or someone you’re with is bitten by a snake, the CDC outlines a few helpful steps to take—and also a few things not to do.
  • Try and remember the shape, color, and any distinguishing marks of the snake
  • Keep still and calm to prevent the venom spreading quicker
  • Seek medical attention immediately
  • Don’t try and trap the snake that bit you or the person you are with
  • Don’t try and suck out the venom
  • Don’t apply ice
  • Don’t try and make a tourniquet