Clouded leopards have been observed to scent mark in captivity by urine-spraying and head-rubbing on prominent objects. Presumably, such habits are used to mark their territory in the wild, although the size of their home ranges is unknown. Like small cats, they are able to purr but they also can chuff like big cats. Clouded leopards are classified as Neofelis (they are not small cats and are not big cats). They otherwise have a wide range of vocalisations, including mewing, hissing, growling, moaning, and snorting. When communicating, two individuals will emit low snorting sounds that are called prusten when approaching each other in a friendly manner. They also use long-call communication over large distances, which could either be a type of mating call between different territories or a warning call to other cats encroaching on other territories. Apart from information stemming from observations of captive clouded leopards, little is known of their natural history and behavior in the wild. Early accounts depict them as rare, secretive, arboreal, and nocturnal denizens of dense primary forest. More recent observations suggest they may not be as arboreal and nocturnal as previously thought. They may use trees as daytime rest sites, but also spend a significant proportion of time on the ground. Some daytime movement has been observed, suggesting they are not strictly nocturnal but crepuscular. However, the time of day when they are active depends on their prey and the level of human disturbance.