As snakes seek warm, dry shelter during the rainy season, encounters in residential areas increase significantly. Knowing which species are venomous and how to distinguish them is important and might be life-saving information.
While many suggest that a snake's head shape or body pattern could indicate venom, this categorisation has proven unreliable, as snakes with similar characteristics can be either venomous or harmless.
Jessada Denduangboripant, a professor at the Faculty of Science, Chulalongkorn University, advised that it is better to remember the seven venomous snake types often encountered in Thailand.
Here are Thailand's seven venomous snakes:
Monocled cobra
The monocled cobra (Photo: Thai National Parks)
The monocled cobra (Naja kaouthia) stands out with its characteristic O-shaped hood marking. Juvenile specimens typically display vibrant yellow, brown, grey, or black colouration with distinctive cross-bands, while mature adults develop paler, brownish or olive tones.
This species features black spots beneath its hood and one to two dark cross-bars on its belly. Extended neck ribs allow dramatic hood expansion when threatened. The snake possesses fixed front fangs moderately adapted for venom spitting.
Primarily nocturnal hunters, monocled cobras frequent both rural fields and urban settlements, including major cities. Their adaptability to human environments makes encounters increasingly common in residential areas.
King cobra
The king cobra (Photo: Thai National Parks)
Thailand's king cobra (Ophiophagus hannah) dwarfs other cobra species, averaging 3-4 metres in length with exceptional specimens reaching 5-6 metres. The species displays golden-iris round eyes and a distinctively large, rounded head.
Regional colour variations occur throughout Thailand, with specimens appearing in black, greyish-green, and brown. The belly ranges from yellow to nearly white, while throat areas show reddish-orange colouration.
Despite their fearsome reputation, king cobras remain generally non-aggressive except during mating seasons or when guarding eggs. When threatened, they rear their front section, expand their narrower hood, expose fangs, and emit loud hissing sounds.
These diurnal hunters occasionally appear at night, preferring forest habitats near water sources.
Banded krait
The banded krait (Photo: Thai National Parks)
The banded krait (Bungarus fasciatus) displays unmistakable alternating black and yellow crossbands encircling its triangular body. Its broad, flattened head blends seamlessly with the neck, while black eyes contrast with distinctive yellow arrowhead markings on an otherwise black head.
Yellow colouration extends to lips, lores, chin, and throat areas. The relatively short tail measures approximately one-tenth of total body length.
These serpents inhabit forests and agricultural areas, often occupying termite mounds and rodent burrows near water sources. They frequently establish territories close to human settlements, particularly in open countryside.
Generally shy and non-aggressive during daylight hours, banded kraits become significantly more active after dark.
Malayan krait
The blue krait (Photo: Thai National Parks)
Also known as the blue krait, the Malayan krait (Bungarus candidus) lacks the distinct triangular body shape of its banded relative. The body features alternating black and white bands, with the first crossband connecting to the dark head colouration.
Some specimens display black-flecked white scales, while others show pale yellowish-white bands alternating with black. The white belly lacks the dark banding that extends to the underside in banded kraits.
These ground-dwelling serpents prefer areas near water sources with high humidity levels. Common throughout much of Thailand, they possess extremely potent neurotoxic venom and remain active primarily at night.
White-lipped pit viper
The male white-lipped pit viper (Photo: Thai National Parks)
The white-lipped pit viper (Trimeresurus albolabris) displays bright yellowish-green colouration, with some specimens showing bluish-green hues. The relatively robust body features a distinctly triangular head and noticeably thicker torso compared to the neck region.
Lip margins and chin typically appear yellow, white, or lighter green than the main body colour. The tail tip shows reddish-brown colouration, while males often display white lines across outer body scales from neck to tail.
Known for aggressive temperament, these vipers strike readily when disturbed. They inhabit wood piles, plant pots, and grass clumps, hunting nocturnally both in trees and on ground level. Common in gardens and residential areas near water sources.
Malayan pit viper
The Malayan pit viper (Photo: Thai National Parks)
The Malayan pit viper (Calloselasma rhodostoma) exhibits reddish-brown or greyish-brown body colouration with dark brown triangular patterns bordered in white running along both sides. These triangular points meet at a brown line following the spine.
The dark brown head features light brown or white lines extending from the nose tip, across the upper eye border, to the upper jaw. The pointed snout curves slightly upward, and vertical pupils characterise the eyes.
Active during twilight and night hours, particularly in high humidity conditions following rainfall, these vipers inhabit sandy areas with leaf litter and wood debris for camouflage. Their colouration and patterns provide excellent environmental camouflage.
This species maintains a reputation for bad temper and lightning-fast strikes.
Eastern Russell's viper
The Eastern Russell's viper (Photo: Thai National Parks)
The Eastern Russell's viper (Daboia siamensis), also known as the Siamese Russell's viper, displays greyish-brown dorsal colouration with small spots between larger spot rows. The underside shows grey suffusion toward the posterior.
These robust, short-bodied serpents with abbreviated tails coil and produce cat-like hissing or tyre-deflating sounds when disturbed. They can strike with remarkable speed even while maintaining coiled positions.
The triangular head bears distinctive black arrow-like markings, while small, ridged scales cover the body. Long venom fangs deliver potent toxins.
These vipers prefer dry plains, hillsides, sandy soil areas, and earth burrows or rock crevices. They hunt exclusively during nighttime hours.
What to do during snake encounters
If you encounter a snake and are unsure if it is venomous, experts advise remaining calm, maintaining a safe distance, and calling for professional help through the emergency hotline 199.
In case of a snake bite, try to remember the snake's characteristics for medical identification, remain as still as possible to prevent venom spread, and immediately call the emergency medical services at 1669 or contact the nearest hospital.
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