Ptyas mucosa, commonly known as the oriental ratsnake, Indian rat snake, 'darash' or dhaman, is a common species of colubridsnake found in parts of South and Southeast Asia. Dhamans are large snakes. Typical mature total length is around though specimens exceeding are not uncommon. The record length for this species was recorded as, second in size perhaps only to their cousin Ptyas carinata among all known living colubrid snakes. Despite their large size, oriental ratsnakes are usually quite slender with even a specimen of commonly measuring only around in diameter. Furthermore, the average weight of ratsnakes caught in Java was around, though larger males of over may easily weigh over. Their colour varies from pale browns in dry regions to nearly black in moist forest areas. Dhamans are diurnal, semi-arboreal, non-venomous, and fast-moving. Dhamans eat a variety of prey and are frequently found in urban areas where rodents thrive.
Adult dhamans have no natural predators other than the king cobras that overlap them in range. Juveniles fear birds of prey, larger reptiles, and mid-sized mammals. They are wary, quick to react, and fast-moving. Dhamans and related colubrids are aggressively hunted by humans in some areas of their range for skins and meat. Harvesting and trade regulations exist in China and Indonesia, but these often go ignored.
Description
Description from Boulenger's Fauna of British India: Reptilia and Batrachia volume of 1890: It is the second largest snake in Sri Lanka, after the Indian rock python. .|alt=
Behavior
Rat snakes, though harmless to humans, are fast-moving, excitable snakes. In captivity, individuals remain highly territorial and may continue to defend their turf aggressively, attempting to startle or strike at passing objects. Rat snakes are diurnal and semi-arboreal. They inhabit forest floors, wetlands, rice paddies, farmland, and suburban areas where they prey upon small reptiles, amphibians, birds, and mammals. Adults, unusually for a colubrid, prefer to subdue their prey by sitting on it rather than by constricting, using body weight to weaken prey. Rat snakes mate in late spring and early summer, though in tropical areas reproduction may take place year round. Males establish boundaries of territory using a ritualised test of strength in which they intertwine their bodies. The behaviour is sometime misread by observers as a "mating dance" between opposite-sex individuals. Females produce 6–15 eggs per clutch several weeks after mating. Adult members of this species emit a growling sound and inflate their necks when threatened. This adaptation may represent mimicry of the king cobra or Indian cobra which overlaps this species in range. The resemblance often backfires in human settlements, though, as the harmless animal is then mistaken for a venomous snake and killed.
