[Last update: 6 June 2022]
Up until yesterday I’ve only seen small sunbeam snakes – about 15 inches long. They are fat and can be found under plastic or other things in muddy water, or anywhere near water. I found one small sunbeam crossing the street at night during a rain in Sisaket – so I pulled him off the road and up into the brush.
Yesterday I saw a 1+ meter snake at a friend’s. The big ones are really impressive. Thick, smooth like glass, and with an unbelievably cool rainbow iridescence that you must see.
Sunbeam snakes get their name because they beam in the sunshine… so to speak. Their scales reflect a luminescence – like a rainbow of colors – and it’s surreal to see a sunbeam snake in the bright sunshine (I have a video for you below, but it doesn’t give justice to the intensity of the rainbow of colors).
Xenopeltis unicolor (Sunbeam Snake)
Thai language: Ngoo sang ateet, Ngoo leu-um deen
Appearance: Sunbeam snakes are thicker than a large banana (with skin) as adults. Their scales are very smooth and the snake has a texture like rubber. Dirt doesn’t appear to stick to the scales. The head is like a shovel blade, tending toward flat. The eyes are small and designed for burrowing in dirt.
Length: Both male and female sunbeams are usually about a meter long with the female growing up to 1.3m for the maximum length (about 4 feet).
Range: All over Thailand. I’ve found them in Trang, Surat, Krabi and Nakhon Si Thammarat provinces. Also found all over Southeast Asia from the Andaman and Nicobar Islands, to Burma (Myanmar), China, Laos, Cambodia, Vietnam, and the Malaysian Peninsula and over to the Philippines.
Habitat: These snakes love the shallow water, muddy areas where they lie hidden under leaves or junk waiting for nightfall. They can be found close to human habitat as well as any lake or other body of water. They are fossorial – meaning, they hide under things – like leaves, dirt, just about anything.
I have found them crossing roads, under stones, and cruising just along the top of a long drainage ditch, peeking down over the rim occasionally to see if they see something.
Notes: These sunbeam snakes rarely bite. They do not do well in captivity and quickly die because they get stressed out. If you keep one – be sure to have soft substrate they can burrow (dig) into to cover themselves. They need cool shade and water. Don’t put them in the sun for long.
Active Time? Nocturnal – night.
Food: Frogs mostly, lizards, geckos, and other snakes. Sunbeam snakes kill prey by squeezing (constricting) it like a python.
Natural Enemies: King cobras and kraits would probably eat these snakes, though I don’t have evidence that they do.
UPDATE – we saw a Malayan Krait (B. candidus) attempt to eat a sunbeam over and over and over but the sunbeam snake was able to twist out of the grip and get the krait in constriction. The sunbeam snake seemed unaffected by the krait’s venom. The krait bit the sunbeam snake over a dozen times as we watched.
Defensive Behavior: Curl tail. Rarely bite. Very low-key, mellow snakes if you’re not provoking them. They move very slow and their scales are good for water but not so great for street, rocks, and other hard smooth surfaces.
Venom Toxicity: None. No danger to humans except possibly a strong bite if you anger it. I’ve heard about only one person ever being bitten by this snake. It just doesn’t typically happen.
Offspring: Little is known. Tough to keep very long – they die quickly in captivity.
Species: X. unicolor
Binomial name: Xenopeltis unicolor
Classification by Reinwardt, 1827
Sunbeam Snake Photo: