The reticulated python is the longest snake in the world, and large reticulated pythons are about 5 to 7 meters long. As of November 2026, zoo pages give 10 meters as the longest on record. As of November 2026, the Guinness World Records longest snake in captivity is Medusa, a captive reticulated python in Kansas City, Missouri. She measured 7.67 meters (25 ft 2 in) on 12 October 2011.

A study of more than 1,000 wild reticulated pythons from southern Sumatra found snakes that measured from 1.5 to over 6 meters in length and from 1 to 75 kilograms in mass. In that study, the largest males were about 5 meters long and 20 kilograms, and the largest females were about 7 meters long and 75 kilograms.

Reticulated pythons live from western Bangladesh to southeastern Vietnam and on islands to the south. They live in tropical forests, often near ponds, rivers and streams, and they prefer temperatures of about 24 to 34 degrees Celsius and high humidity. A python needs an area near a body of water, both for protection and for hunting success.

In Singapore, reticulated pythons move around the city through drainpipes and swim in canals. There they do not tend to grow as large as they do elsewhere, and they usually eat small mammals such as rats.

Reticulated pythons do not have ears; a small bone called the columella lets the python sense vibrations in the ground. A python is virtually deaf to airborne noises, so it relies on its sense of smell and touch. It smells by flicking its forked tongue to bring air particles to a vomeronasal organ on the roof of the mouth.

Only pit vipers, pythons and some boas have pit organs for sensing infrared, or heat. These pit organs let a python respond to heat even in complete darkness, working with vision or on their own. The heat-sensing channel TRPA1 was identified as the infrared receptor in pit-organ snakes, and it is under strong positive selection in pit-bearing snakes, but not in snakes without pits or in other vertebrates. In a lab study of Burmese pythons, a relative of the reticulated python, pythons trained to choose a 37 degree Celsius target over a 24 degree one chose correctly 76 percent of the time, compared with 50 percent by chance. In lab tests, Burmese pythons still chose better than chance when the warm and cool targets differed by only 0.5 degrees Celsius.

A reticulated python hunts by waiting in ambush until food comes close. It has many sharp teeth that curve backwards, but it has no venom. Pythons are good swimmers and often spend time in water, where a large snake moves more easily and can hide while it waits for food. Young pythons spend a lot of time off the ground in trees and bushes, while large adults stay mostly on the ground.

In the Sumatra study, small reticulated pythons fed mostly on rats, and at 3 to 4 meters in body length they shifted to larger mammals such as pangolins, porcupines, monkeys, wild pigs and mouse deer. Bigger pythons of both sexes ate larger prey and ate more often than smaller ones. In a Sumatran study, females shifted from eating rats to larger mammals at a smaller body size than males did, and their feeding frequency rose faster with size. Documented prey of reticulated pythons include small bats, tree shrews and deer.

A reticulated python swallows its food whole. A snake has a very low metabolic rate, so it can go a long time between meals. In a zoo, large reticulated pythons are fed about 10 pounds of rabbits every 3 to 4 weeks.

One study of about 1,000 reticulated pythons from southern Sumatra measured clutch size, how often females breed and fat stores, and found strong links between body size and these traits. In a study of 784 harvested pythons at four places in northern Sumatra, females laid large clutches (mean 24.2) of eggs each heavier than 250 grams, but bred only once every 2 to 4 years. Pythons in northern Sumatra mature at larger body sizes than those in southern Sumatra, and their breeding season is shifted, probably because the two areas lie on opposite sides of the equator. The bigger a female python is, the more eggs she lays, and male pythons begin to breed at about 7 to 9 feet long, and females at about 11 feet long. A 1998 study of reticulated pythons found giant pythons near or beyond the extremes of what is reported for smaller snakes in traits such as clutch size and maternal body size. A 1998 study also suggests that current generalizations about how life-history traits scale with body size in snakes may be premature.

A clutch usually holds about 25 to 50 eggs, though in Singapore females lay clutches of 15 to 80 eggs. A female keeps the eggs warm by shivering, a process of muscle contractions called shivering thermogenesis that speeds incubation. A female can also store a male's sperm until climate conditions are better. Parthenogenesis, in which a female produces offspring without a male, has been documented in captive pythons, although it is uncommon. The eggs hatch after about 80 to 90 days, and the mother guards them and defends them against predators.

A 2014 study of boas and pythons built a family tree of 84.5 percent of boid species and 82.5 percent of pythonid species, using an 11-gene dataset. A molecular study of this family tree placed the reticulated python in a new genus, Malayopython, together with the Timor python. The Reptile Database lists three subspecies of Malayopython reticulatus: M. r. reticulatus, M. r. saputrai and M. r. jampeanus. A molecular study of the boa and python family tree suggests that the large Python species of southern Asia evolved giant size separately from the giant Australasian pythons Malayopython and Morelia.

Researchers made 527 nocturnal boat surveys, covering 2,427 kilometers along a 64-kilometer stretch of Sabah's Kinabatangan River, from April 2016 through March 2021. In that survey, the average chance of detecting a python was only 20.5 percent, and a python was missed 25 percent of the time even where it was known to be present. The researchers recorded 159 python encounters, 83 on standardized surveys and 76 by chance, but only 25 individuals were recaptured across 40 events. As of September 2026, the Kinabatangan work is described as the most intensive field research ever conducted on free-ranging reticulated pythons.

The Kinabatangan researchers concluded that field-based population viability analysis is functionally impossible for reticulated pythons because they are so camouflaged and hard to detect. They recommend monitoring harvested pythons over time for body size, body condition and sex ratios, instead of relying on field counts, to tell whether trade is sustainable.

Adult reticulated pythons are so big that they have few natural predators. As of September 2026, reticulated pythons have been commercially harvested in Malaysia and Indonesia for more than a century, with hundreds of thousands taken from the wild each year for meat, skins and medicine body parts. The apparent ability of reticulated python populations to withstand heavy harvesting may reflect their rapid growth, early maturation, high fecundity, flexible diets and habitat use, and ability to evade detection. In northern Sumatra, very large females were rarely captured, which may reflect size-related shifts in the habitats they choose. As of November 2026, the IUCN Red List lists the reticulated python as Least Concern. In 1999, researchers who studied reticulated pythons in northern Sumatra raised doubts about the long-term sustainability of the offtake from the wild.

A reticulated python must shed its skin as it grows, because it keeps growing throughout its life. In the wild, reticulated pythons live about 15 to 22 years. As of November 2026, the longest known lifespan of a reticulated python in captivity is 32 years, and the longest in the wild is 23 years.

Words to know

• infrared: heat energy
• parthenogenesis: birth without father
• fecundity: ability to breed
• camouflaged: hidden by color
• sustainable: able to continue