Venomous or not? Snake identification guide by region

Pick your region to see the main venomous snakes and the harmless snakes most often mistaken for them. No single feature (head shape, pupil shape, colour) reliably identifies a venomous snake worldwide. If you are unsure, assume it is venomous, keep your distance and never handle it. See our safety and first aid page.

Region:

North America (USA & Canada)

Snake	Status	Key features
Rattlesnakes	Venomous	Rattle or button on tail tip, heat pit between eye and nostril, vertical pupils, heavy body.
Copperhead	Venomous	Tan to copper body with dark hourglass-shaped crossbands (narrow on the back, wide on the sides).
Cottonmouth (water moccasin)	Venomous	Thick dark body, white mouth lining shown when threatened, often swims with whole body riding on the surface.
Coral snakes	Venomous	Red, yellow and black bands where red touches yellow (US species only; the rhyme fails elsewhere).
Gopher / bull snake	Harmless	Shakes tail and hisses to imitate a rattlesnake but has no rattle; round pupils.
Northern water snake	Harmless	Often mistaken for cottonmouth or copperhead; round pupils, swims with mainly the head above water.
Milk snakes & scarlet kingsnake	Harmless	Red bands touch black bands, not yellow.

United Kingdom & Europe

Snake	Status	Key features
Adder (common European viper)	Venomous	Dark zigzag stripe along the back, vertical pupils, red or copper eyes. The UK's only venomous snake.
Asp viper & nose-horned viper	Venomous	Southern and central Europe; upturned snout or 'horn', vertical pupils.
Grass snake	Harmless	Yellow-and-black collar behind head, round pupils, often near water; may play dead.
Smooth snake	Harmless	Rare in the UK; slender, grey-brown with small paired spots and a dark stripe through the eye; round pupils.

Australia

Snake	Status	Key features
Eastern brown snake	Venomous	Highly variable colour (tan to almost black), slender and fast. Colour alone cannot identify it.
Tiger snake	Venomous	Often banded but can be plain; flattens neck when threatened.
Red-bellied black snake	Venomous	Glossy black back, red or pink lower sides; usually near water.
Death adders	Venomous	Short, stout, triangular head, thin tail tip used as a lure.
Carpet python	Harmless	Non-venomous constrictor; heat pits along lips, intricate blotched pattern; can still bite.
Common tree snake	Harmless	Slender, green-olive with yellow belly, very large eyes.

South Asia (India, Sri Lanka, Pakistan, Bangladesh)

Snake	Status	Key features
Spectacled cobra	Venomous	Raises and spreads a hood, often with a spectacle-like mark on the back of the hood.
Common krait	Venomous	Glossy black or blue-black with thin white paired bands; active at night, often enters homes.
Russell's viper	Venomous	Three rows of dark brown chain-like spots on a tan body; loud hiss.
Saw-scaled viper	Venomous	Small, rubs coils to make a rasping sound; arrow or cross mark on head.
Indian rat snake	Harmless	Large, fast, often mistaken for a cobra but has no hood.
Common wolf snake	Harmless	Brown with pale bands; resembles a krait but is not venomous.

Sub-Saharan Africa

Snake	Status	Key features
Puff adder	Venomous	Thick body with pale chevrons, relies on camouflage and may not move away.
Black mamba	Venomous	Long, grey-brown (not black), coffin-shaped head, inky-black mouth lining.
Green mambas	Venomous	Bright green, slender tree snakes in East, West and southern Africa.
Boomslang	Venomous	Rear-fanged tree snake with huge eyes; colour varies by sex. Bites are rare but serious.
Spitting cobras	Venomous	Can spray venom toward the eyes from a distance; protect eyes and back away.
Spotted bush snake	Harmless	Green with black spots on front half; often confused with green mambas.
Brown house snake	Harmless	Brown with pale lines on the head; common around homes, eats rodents.

Central & South America

Snake	Status	Key features
Lancehead (fer-de-lance, Bothrops)	Venomous	Triangular head, pit between eye and nostril, X- or triangle-shaped markings; a leading cause of bites.
Bushmasters	Venomous	Very large pit vipers with rough, keeled scales; live in rainforests.
Coral snakes	Venomous	Many banding patterns; colour rhymes do NOT work here. Treat any banded red snake with caution.
False coral snakes	Harmless	Mimic coral snake colours; cannot be reliably told apart by non-experts.
Boa constrictor	Harmless	Non-venomous constrictor with saddle-shaped blotches, darker toward the tail.

Simplified educational guide, not a field key. Local wildlife services and herpetological societies can help identify snakes from photos.