When diving under water, they undulate their bodies and tails. Captive otters swim at speeds of . Observations of wild Asian small-clawed otters revealed that they smear their spraint at latrine sites, using their hind feet and tails. Large groups smeared more than groups of three or fewer animals. The frequency of latrines with smeared scats varied in different locations, indicating a preference for certain sites. Spraint smearing most likely facilitates social ties among group members and is associated with territorial marking displays. They use grassy or sandy banks for resting, sun bathing and grooming. In marshes, they use mostly islands. Diet The Asian small-clawed otter feeds mainly on crabs, mudskippers and Trichogaster fish. Its diet varies seasonally. When and where available, it also catches snakes, frogs, insects, rats and ricefield fish like catfish, Anabas testudineus and Channa striata. The size of crabs found in spraints in Huai Kha Khaeng Wildlife Sanctuary ranged in carapace width from . Captive Asian small-clawed otters were observed to leave shellfish in the sun so the heat causes them to open, making it possible for them to eat them without having to crush the shells. Reproduction Information about the Asian small-clawed otter's mating and breeding behaviour has been studied in captive environments. Captive pairs are monogamous. The estrous cycle of females lasts 28 to 30 days with estrus lasting between one and 13 days. Usually, mating takes place in the water. Gestation lasts 62 to 86 days. Interval between births is at least eight months. About two weeks before parturition, both female and male engage in building a nest. They collect grass, hay or straw and carry this material into the breeding chamber. Between one and seven pups are born in a litter. Pups are born with closed eyes, which open in the fifth week. Newborn pups weigh between and reach a weight of after 60 days. They start exploring the environs of the breeding den at the age of ten weeks. At about three months, they enter and paddle in shallow water under the guidance of the mother. They become independent at the age of four to five months. Threats The Asian small-clawed otter is threatened by poaching for its fur, loss and destruction of habitats such as hill streams, peat swamp forests and mangroves for aquaculture projects. Threats in India include deforestation, conversion of natural habitat for tea and coffee plantations, overfishing