How to Identify Venomous Snakes

Learn about snakes. There are four venomous snake species in the U.S.: the cottonmouth, rattlesnake, copperhead, and coral snake.

Cottonmouth (Water Moccasin). The cottonmouth has elliptical pupils and a color range from black to greenish hues. A distinct white stripe runs along the sides of its head. Though commonly found in or near water, these snakes are also well-adapted to life on land. Juveniles have bright yellow tails. They tend to be solitary creatures, so if you spot a group of snakes peacefully coexisting, they are likely not cottonmouths.

Rattlesnake. Look for the signature rattle at the tail's end. Some non-venomous snakes mimic the rattling sound by rustling their tails in dry leaves, but only rattlesnakes have the distinctive segmented rattle. If the rattle isn’t visible, check for a triangular head and elliptical, cat-like pupils—clear indicators of a rattlesnake.

Copperhead. This species has a body shape similar to the cottonmouth but is much lighter in color, ranging from coppery brown to bright orange, pinkish-silver, or peach. Juvenile copperheads also feature a yellow-tipped tail.

Coral Snake. Beautiful yet highly venomous, coral snakes resemble some harmless species like milk snakes. However, their distinctive coloration—with black, yellow, and red bands, a yellow head, and a black-tipped snout—sets them apart. A common rhyme helps differentiate them: 'Red touches yellow, kill a fellow. Red touches black, friend of Jack.' Despite their potency, coral snakes are reclusive and rarely bite. No fatalities have been recorded from Arizona coral snakes, and only a handful of cases exist in the south-central and southeastern U.S.

Observe Color Patterns. Venomous snakes in the U.S. often display multiple colors, whereas most solid-colored snakes are harmless. However, this rule has exceptions—cottonmouths are venomous despite their more uniform coloration. Additionally, be cautious of captive venomous snakes that may have escaped their enclosures.

Check the Head Shape. Non-venomous snakes typically have a rounded, spoon-shaped head, while venomous snakes have a distinct triangular head due to their venom glands. This characteristic is not as prominent in coral snakes.

Look for a Rattle. If a snake has a rattle at the end of its tail, it is a venomous rattlesnake. However, some non-venomous snakes mimic the rattling sound by shaking their tails, but without the segmented rattle, the noise is more like a faint rustling, similar to shaking a salt shaker.

Identify Heat-Sensing Pits. Certain venomous snakes in the U.S. have small pits between their eyes and nostrils, which help them detect the body heat of their prey. Coral snakes do not have this feature.

Be Aware of Mimicry. Some non-venomous snakes imitate the appearance and behavior of venomous ones. Rat snakes can resemble rattlesnakes, while milk snakes and king snakes have patterns similar to coral snakes.

• Always treat an unidentified snake as if it were venomous. While caution is necessary, avoid killing snakes—this may be illegal, and eliminating non-venomous snakes can lead to an increase in venomous snake populations and other harmful creatures.

The Cottonmouth (Water Moccasin) Has Elliptical Pupils, While Harmless Water Snakes Have Round Pupils. Regardless, it’s best to leave the snake alone and let it move away on its own.

Beware of the Adder! The adder is the UK's most common venomous snake, distinguished by a V- or X-shaped marking on its head. Other key features include slit-like vertical pupils, dark zigzag patterns along its back, and dark oval markings on its sides. Their coloration varies from gray-blue to black, with gray-blue being the most typical, though some individuals may appear brown or reddish.

• Adders are widely found across the UK, especially in southern regions. While their bites are painful and require immediate medical attention, fatalities are rare.
• They are not particularly aggressive and usually avoid human interaction unless provoked.

Watch Out for the Big Four. India is home to many snake species, including several venomous ones, but the 'Big Four' are particularly widespread and highly dangerous.

Common Cobra. When picturing snake charmers and cobras emerging from baskets, this is the species that comes to mind.

• They range in length from 0.9m to 1.8m, with broad heads. Their distinctive hood expands when threatened, creating an intimidating display.
• Color varies by region: southern Indian cobras are typically yellow to brown, while northern Indian cobras tend to be darker brown or black.
• Though generally shy, they will strike if provoked, sometimes delivering multiple bites. Larger specimens can latch on and inject a high volume of venom.
• A cobra bite is a medical emergency—this species is responsible for numerous snakebite fatalities across India.

Common Krait. The common krait measures between 1.2m and 2m in length. Its head is slightly depressed and broader than its neck, with a rounded snout. Its eyes are small and completely black.

• The body is black with single or paired milky-white bands. The scales have a hexagonal shape, and the subcaudal scales are fused.
• These nocturnal snakes remain hidden in dark, dry places during the day. They are docile and avoid humans in daylight but become defensive and may bite if disturbed at night.

Russell’s Viper. A robust viper with a brown body tinged with red and yellow. It features three longitudinal rows of dark brown or black eye-like spots that start from the head and fade towards the tail. The side spots are smaller and rounder than those on its back.

• Its triangular head tapers at the snout and expands significantly at the neck. The head has two triangular marks. The eyes have vertical slit pupils, and its tongue is black with a purplish tint.
• Russell’s viper venom is highly potent, requiring immediate medical attention. If provoked—even beyond accidental contact—it produces a loud, pressure-cooker-like hissing sound as a warning.

Saw-Scaled Viper. The second most common venomous snake in India after Russell’s viper. These snakes range from 40cm to 80cm in length, with a body color varying from deep brown to reddish, gray, or mixed shades. They have pale yellow or very light brown spots, with interwoven dark markings along the body.

• Highly aggressive when provoked, they produce a rasping noise like a saw by rubbing their dorsal scales together. If you hear this sound, retreat immediately—this species is among the fastest-striking snakes in the world.
• Any bite from this snake requires medical treatment. Some bites may be ‘dry’ (without venom), but only a medical professional can determine that.

Inland Taipan. Also known as the ‘fierce snake,’ the inland taipan holds the title for the most venomous snake on Earth. Its venom is the most potent of any known species, yet there are no recorded human fatalities from its bite.

• It can grow up to 1.8m in length, with a body color ranging from dark brown to pale yellow. Its coloration darkens in winter and lightens in summer. The head is nearly entirely black.
• It inhabits the black soil plains where Queensland, South Australia, and the Northern Territory intersect.

Eastern Brown Snake. While the inland taipan holds the title for the most venomous snake, the eastern brown snake is responsible for the most snakebite fatalities in Australia. Like most snakes, it prefers to flee rather than fight, but if cornered, grabbed, or stepped on, it will strike without hesitation.

• Growing over 2m in length, this species is highly agile, particularly on hot days. Its sleek body ranges in color from pale golden brown to gray or dark brown. The underside is lighter, often speckled with deeper orange spots.
• Its habitat stretches across eastern Australia, from arid deserts to coastal regions, favoring grasslands and forests.
• If bitten, seek emergency medical attention immediately.

• Remember, snakes fear us more than we fear them. They only bite when startled or threatened, especially venomous species. Be cautious when walking outdoors.
• Stay alert and survey your surroundings. Make noise to give snakes a chance to retreat before you get too close.
• In areas where both coral snakes and non-venomous milk snakes are present, recall the saying: "Red touches yellow, kill a fellow; red touches black, friend of Jack." This rule only applies in eastern North America!
• Avoid placing hands or feet in areas you can't see—many climbers suffer bites this way.
• Never handle a snake unless you're certain it's non-venomous, and never keep venomous snakes as pets.
• Wear sturdy boots, thick socks, and durable long pants (avoid shorts) when traveling in snake-prone areas. Herpetologists often wear knee-high boots in such environments.
• Due to sudden fear responses, most snakes release a large amount of venom when they bite. However, older and larger snakes may conserve venom—but even a small dose can be deadly.
• If a snake is spotted in a residential area, inform neighbors. This helps ensure the safety of children and pets, especially if the snake is venomous.
• Education is the most powerful tool for snake safety. Learn to recognize local snake species. A field guide can be invaluable.
• If you encounter a snake in dense vegetation, back away slowly. Stick to short grass whenever possible to avoid unexpected encounters.
• Snakes can climb trees, so be aware of your surroundings, not just the ground.

• Many venomous snake species in the U.S. are endangered. It is illegal to kill or interfere with protected species, including venomous ones. Additionally, many states prohibit the killing, capturing, harassing, or possessing of any wild snake, venomous or not.
• Judging a snake’s danger by its eyes is unreliable. Highly venomous snakes like cobras and black mambas have round pupils, while harmless species like red-tailed boas and green tree pythons have elliptical pupils. Never assume a snake is safe just because it has round eyes.
• Some snakes appear harmless but are venomous, while others seem dangerous but are not. It’s essential to know the snakes in your area.
• Do not disturb or approach a snake just to identify it unless you are certain it is non-venomous. Most snakes prefer to avoid humans.