Indian rat snake

Identification

The Indian rat snake is a large, slender snake with a distinct head, a large eye with a golden iris and a long, whip-like tail^1,2,3. Its back is yellowish, olive, grey or brown, usually with dark bands towards the tail, and its whitish lip scales are edged with black^2,3. Young snakes have light crossbars on the front of the body².

Most adults are about 1.5–2 m long, and the largest wild snakes usually measure 2–2.5 m^2,3. Lengths over 3 m have been reported⁴. Hatchlings are roughly 30–47 cm long^2,3.

Distribution

The Indian rat snake has a very large range. The Reptile Database lists it from Iran, Turkmenistan and Afghanistan, through Pakistan, India, Sri Lanka, Nepal, Bhutan and Bangladesh, to Myanmar, southern China, Taiwan, Thailand, Laos, Cambodia, Vietnam, Malaysia and the Indonesian islands of Sumatra, Java and Bali¹. It is found across most of India¹.

Habitat

The Indian rat snake lives in many kinds of open country, including farm fields, scrub, grassland and the edges of ponds, reservoirs and rural gardens³. It is abundant in farmland across southern Asia⁴. On farms it sometimes enters houses while searching for rodents³. It is partly a tree-climber¹.

Behaviour

The Indian rat snake is active by day^3,5, although it is also known to forage at night at times⁵. When cornered or caught it defends itself vigorously: it may strike, bite repeatedly and release faeces³.

Diet

The Indian rat snake eats a wide range of animals, mainly frogs and toads, rodents, lizards, birds and other snakes^3,5. Large adults are more likely than young ones to eat snakes, and one in Mumbai was seen swallowing a live Indian rock python⁵. Rat snakes have also been recorded swallowing odd items such as pieces of cloth and plastic⁵.

Reproduction

The Indian rat snake lays eggs¹. In a study in Java, clutches held 7 to 25 eggs, and a later study there found an average of about 12.6 eggs, with bigger females laying more^2,4. The eggs hatch after about two months³. Snake collectors in Java report that young rat snakes grow quickly and can mature in about nine months².

Venom and medical significance

The Indian rat snake is non-venomous and harmless to people^3,6. A large, frightened rat snake can still bite hard and repeatedly if it is handled or cornered, so it is best left alone³. Because harmless and dangerous snakes can look alike, anyone bitten by a snake that has not been identified with certainty should seek medical care immediately⁶.

Conservation

The Indian rat snake is listed as Least Concern on the IUCN Red List (assessed in 2021)⁷. It is heavily hunted for its skin and meat in parts of South-East Asia, especially Java, but a comparison of harvested snakes taken 25 years apart found no change in their size or breeding traits, suggesting the harvest there has been sustainable^2,4. In India it is protected under Schedule I of the Wild Life (Protection) Act⁸.

Similar species

The Indian rat snake can be confused with the Indian cobra (Naja naja). Unlike a cobra, a rat snake cannot spread a hood, and it has a large eye and black-edged lip scales^2,3. It also has small loreal scales between the nostril and the eye, which cobras and other elapids lack⁶. The similar Indo-Chinese rat snake (Ptyas korros) has plain lip scales without black edges². These differences are not a safe basis for handling any snake. Treat any snake you cannot identify as potentially dangerous.

In captivity

In India the Indian rat snake, also called the dhaman, is listed in Schedule I of the Wild Life (Protection) Act, as amended in 2022, giving it the strongest category of legal protection⁸. It is a wild animal that should not be caught or kept as a pet.