Morelia spilota, commonly referred to as Carpet Pythons and Diamond Pythons, is a large snake of the family Pythonidae found in Australia, New Guinea (Indonesia and Papua New Guinea), Bismarck Archipelago, and the northern Solomon Islands. There are many subspecies. The Carpet Python is a large species of python in the genus, reaching between 2 to 4 metres (6.6 to 13.1 ft) in length and weighing up to 15 kilograms (33 lb). M. s. mcdowelli is the largest subspecies, regularly attaining lengths of 2.7–3 m (8.9–9.8 ft). M. s. variegata is the smallest subspecies, averaging 120–180 cm (3.9–5.9 ft) in length. The average adult length is roughly 2 metres (6.6 ft). Males are typically smaller than females. In some regions, females are up to four times heavier. The head is triangular with a conspicuous row of thermoreceptive labial pits. The coloring of Carpet Python is highly variable, ranging from olive to black with white or cream and gold markings. The patterning may be roughly diamond shaped or have intricate markings made up of light and dark bands on a background of gray or a version of brown.
Carpet Pythons are found in a wide variety of habitats, from the rainforests of northeastern Queensland through the River Red Gum/Riverbox woodlands of the Murray and Darling Rivers, to the arid, treeless islands of the Nuyts Archipelago off the South Australian west coast. They are often found near human habitation where they perform a useful service by eating rats and other vermin. Morelia spilota is known to occur in areas that receive snowfall. Morelia spilota are semi-arboreal tree snakes. They do not completely rely on trees, however, and are capable of moving around elsewhere. Morelia spilota are also found in temperate grasslands with hot and dry weather. Carpet pythons kill prey by constricting it until it suffocates. In the wild, their diet consists mainly of small mammals, birds, and lizards. Incidents of Carpet pythons devouring small dogs have been reported.
Carpet Pythons are a popular pet among snake enthusiasts. Some forms can be more irascible than others, such as M. s. mcdowelli and M. s. variegata. Forms that tend to be more even tempered include Morelia spilota and M. s. metcalfei. However, this is not a hard rule. Although they can grow to a reasonable size (2–3.5 m) and can be nippy as hatchlings, most will grow into docile adults. However, care must be taken when feeding, as these snakes have a strong "feeding response" behaviour that can be mistaken for aggression. Captive specimens are normally fed live or frozen rats. They may have a lifespan of 15 to 20 years.
The Carpet python is oviparous, with females laying 10–50 eggs at a time. Afterward, females coil around the eggs to protect them and keep them warm through using muscular contractions to generate heat. This type of maternal care, which is typical for pythons, ceases once the hatchlings have emerged. Most carpet pythons are annual breeders, and cycling them on a yearly basis will yield the best results. Gradually reducing the nighttime low temperatures (aim for 65 to 70 degrees Fahrenheit) and daily photoperiod (10 to 12 hours) will start the breeding process, usually in the fall. Daytime basking temperature should remain at least 90 degrees. Females should be given some extra meals prior to breeding season to build up some fat reserves that will be needed for egg formation and oviposition. This is especially critical when allowing the female to incubate her own eggs (maternal incubation), a unique behavior in carpet pythons that can be exciting to witness. While females are best kept slightly plump at the beginning of breeding season, males should be kept lean and muscular for optimal breeding vigor. Males will often stop eating during breeding season and display cruising behavior in their cage, relentlessly crawling in pursuit of a mate. Males are usually sexually mature by about 17-18 months of age. Carpet Pythons reach sexual maturity at 18 months to 4 years of age. Breeding size occurs at 4'+ depending on subspecies. Irian Jayas breed at 4'+, Jungles at 4-6', Coastals at 6-8', Bredli's at 4-6', and Diamonds at 6-8'. Breeding season is from November to March, stop all feeding at this time. Both animals should be in excellent condition before any breeding is attempted. Clutch size can range from 10-40 eggs depending on the size of the female.