Snakes are interesting animals that come in many different sizes and shapes. However, some species of snakes have a distinct feature that sets them apart from others: a triangular-shaped head. Although most people assume that snakes with triangular heads are venomous, you might be surprised to learn that there are actually a few non-venomous species that share this trait as well.
In this article, we’ll learn about some of the snakes in North America that have this trait, as well as some information about them.
12 Snakes with triangular heads
Here’s a list of 12 snake species that have triangular shaped heads.
- Scientific Name: Agkistrodon piscivorus
Cottonmouths are one of the most common types of venomous snakes found in the United States. Despite being non-aggressive and only biting humans when provoked, it’s one of the most feared due to its fatal venom.
You’ll commonly see them in creeks, ponds, lakes, and marshes with shallow, slow-moving water. These large snakes can also grow up to 48 inches in length and can be solid brown, black, or yellow in color, with dark bands covering their entire backs. Their characteristic triangular-shaped heads also make them easy to spot as venomous snakes.
2. Mojave green
- Scientific Name: Crotalus scutulatus
The Mojave greens are extremely venomous and can be found in the southwestern United States’ deserts. They can be found in a variety of habitats, from the dry desert to grasslands and bushes, where these reptiles can be seen feasting on kangaroo rats and other rodents.
Depending on where they live, individuals of this species can be anywhere from brown to pale green, with a brown or tan diamond pattern across their back.
3. Timber rattlesnake
- Scientific Name: Crotalus horridus
The timber rattlesnake is a common rattlesnake found in the eastern half of the United States. The length of these vipers can reach up to 114 centimeters, and they can be brown, yellow, or gray in color. They can be recognized by the triangular shape of their heads, their black tails, and the bands that run along their backs.
The venom of this species can kill a person, but it doesn’t happen very often. Timber rattlesnakes are more likely to run away and hide when they feel threatened than to strike out and bite.
4. Arizona black rattlesnake
- Scientific Name: Crotalus cerberus
The Arizona black rattlesnake is known for being the first snake species that was seen to have complex social behavior. You can identify them through their dark brown or black background with blotches that are edged with white or yellow.
In their natural environments, which are typically pine-oak woodlands or chaparrals, they prey on a variety of amphibians, reptiles, birds, and mammals.
5. Brown water snake
- Scientific Name: Nerodia taxispilota
If you think all snakes with triangular heads are venomous, the brown water snake will prove you wrong. The brown water snake is a true water snake species distinguished by its triangular head, which leads to its common misinterpretation as a venomous snake. However, these creatures are completely harmless, and they’re excellent swimmers that can be found in a variety of rivers and streams.
The body of this creature is light to dark brown, with large square spots of dark brown. They can climb well, so you might spot them basking in a tree or on a branch above the water.
6. Massasauga rattlesnake
- Scientific Name: Sistrurus catenatus
The Massasauga rattlesnake is one of the venomous snakes that you can find in midwestern North America. This snake can grow to be between 18 and 30 inches in length and has a triangular head; its gray body is covered in dark brown or black spots, with three rows of smaller dark spots on either side.
Massasauga snakes are venomous, but they’re afraid of humans and will usually run away if they see one. Their short fangs limit the amount of venom they can inject, making human fatalities extremely unusual.
7. Panamint Rattlesnake
- Scientific Name: Crotalus stephensi
The Panamint Rattlesnake is a type of rattlesnake that lives in southern California and Nevada. It has a body color that varies from tan to gray with blotches of brownish coloration, and its head is broad and triangular in shape.
You can usually find them in hilly or mountainous regions with a multitude of rocks, as this is an ideal environment for their natural camouflage. The majority of their diet consists of birds, lizards, and small mammals, all of which they hunt by ambushing.
8. Narrow-headed garter snake
- Scientific Name: Thamnophis rufipunctatus
Due to its triangular head shape, the narrow-headed garter snake may be mistaken for a venomous snake. This species of garter snake is found only in the southwestern United States, and it lacks the characteristic stripes of other garter snakes.
They have a grayish body with irregular dark spots, and since they’re among the most aquatic of the garter snakes, you can usually find them near rivers or streams. Despite their triangular heads, they’re non-venomous and harmless to humans. Fish is also their main source of food.
9. Eastern copperhead
- Scientific Name: Agkistrodon contortrix
Found across much of the central and eastern United States, the eastern copperhead is one of several venomous snake species with triangular heads. They prefer dense undergrowth, so you’ll find them in places like wooded hillsides and the edges of swamps. When a copperhead senses danger, it’ll usually lie flat on the ground and stay there until the danger passes.
You can identify them with their gray, copper, tan, or pinkish-tan body color with hourglass-shaped bands on their back.
10. Eastern diamondback rattlesnake
- Scientific Name: Crotalus adamanteus
The Eastern diamondback rattlesnake is the largest of the United States’ rattlesnake species. It’s typically between 3 and 6 feet in length, but individuals over 7 feet in length have been documented. They can be distinguished from non-venomous snakes by their triangular heads, which clearly indicates that they’re venomous.
Scrublands, coastal forests, and pine flat woods are just some of their common environments. The eastern diamondback rattlesnake also gets its name from the distinctive diamond-shaped pattern found on its back.
11. Pygmy Rattlesnake
- Scientific Name: Sistrurus miliarius
The Pygmy Rattlesnake is a small, venomous snake that can reach lengths between 14 and 30 inches. This species is easily recognized by its variable coloration from light to dark gray, with large black blotches in the back alternating with reddish-brown. They have a short and stocky bodies with a head that are triangular, just like other venomous snakes.
The sandhills, forests, and flatwoods are just some of the places you might spot this species. Pygmy rattlesnakes may be the smallest rattlesnake in the United States, but they’re still capable of inflicting painful but not fatal bites.
- Scientific Name: Crotalus cerastes
The Sidewinder snakes are venomous reptiles that can be found in the Mohave Desert as well as the Sonoran Desert. This snake is commonly found in deserts with very sandy areas, and it’s able to do so because it uses a locomotion strategy known as side-stepping.
Even though their venom is typically less potent than that of other types of rattlesnakes, someone who has been bitten by one of these vipers still needs medical attention.