What Kind of Water Snake Do You Spy in Your Local Pond?

The pattern on this juvenile northern water snake help explain one of it's colloquial names: the banded water snake. James Gerholdt / Getty Images

Have you ever seen a snake in or near a river or pond? It was probably a water snake! These slithery swimmers are easy to spot anywhere the world gets a little wetter, particularly near freshwater.

Water snakes are some of the most fascinating reptiles you’ll find in North America’s aquatic environments. These nonvenomous snakes are perfectly adapted to life in the water, where they hunt, swim and thrive.

Although they are often mistaken for the venomous cottonmouth, water snakes are harmless to humans and play an essential role in maintaining the health of their ecosystems. Let’s dive into the very specific aquatic snake niche and explore some of the most common species you might encounter.

Northern Water Snake

The northern water snake (Nerodia sipedon sipedon) is one of the most common water snakes in North America. With a slender body and a pattern of dark blotches along its back, the northern water snake is often seen swimming in lakes, rivers and ponds.

These snakes are highly adaptable and easy to find throughout the eastern United States as well as southern Canada. The common northern water snake is known for its aggressive defense when threatened. Still, despite its intimidating display, it’s completely nonvenomous. This species plays a crucial role in controlling fish and amphibian populations.

People will sometimes colloquially call this animal an eastern water snake because of where it's spotted, or even a northern banded water snake. The bands are more prominent in younger snakes and tend to fade with age.

Brown Water Snake

The brown water snake (Nerodia taxispilota) is a large, heavy-bodied snake found primarily in the southeastern United States. This snake is often mistaken for the venomous cottonmouth due to its thick body and dark coloration, but it's actually harmless.

Brown water snakes have a pattern of large, dark blotches along their necks and backs. Expect to see them basking on branches overhanging rivers or swimming in search of prey. They primarily feed on fish, and their presence is a good indicator of a healthy aquatic ecosystem.

Lake Erie Water Snake

The Lake Erie water snake (Nerodia sipedon insularum) is a subspecies of the northern water snake found exclusively on the Lake Erie islands. They've adapted to life in and around the lake's western islands offshore.

These water snakes are slightly larger and paler than other northern water snakes. Although they were once threatened by habitat loss and human persecution, conservation efforts have helped their population recover. They primarily feed on fish, particularly the invasive round goby, which has helped them thrive in their unique habitat.

Plain-bellied Water Snake

The plain-bellied water snake (Nerodia erythrogaster) is a large, nonvenomous snake most common in the southeastern United States.

Unlike other water snakes, the plain-bellied water snake has a uniformly colored underside, which can range from yellow to red. Its back is usually dark brown or gray, with no distinct pattern, making it easy to distinguish from other species.

The plain-bellied water snake prefers slow-moving waters, such as swamps, marshes and ponds.

Despite its large size and intimidating appearance, this is another snake you don't have to worry about if you see it in the wild. Treat it with respect, but take some solace in the fact it doesn't have any venom to do a number on you.

We created this article in conjunction with AI technology, then made sure it was edited and fact-checked by a HowStuffWorks editor.