Playful and proud, river otters are born to have fun. At least, it appears that river otters are having fun, because of their playful antics with each other, as well as their facial and body expressions. By any measure, otters are extremely curious and intelligent mammals.
Adult river otters reach a length of about 127 centimeters, including their tails, which are nearly one third of that length. Adults weigh between five and fourteen kilograms. Females are slightly smaller than males. River otters have a dense, short fur with great water resistance. Air is trapped beneath their dense furry coats and acts as insulation against the cold water, where these mostly aquatic mammals feed. Otters roll and rub themselves on sand, rocks, old logs, and even snow in their coat grooming activities. These carnivorous mammals mostly feed on fish. Crayfish also serve as diet items when abundant. Researchers have found that river otters feed directly on fish proportionally to their availability and inversely to the fish's swimming ability. Shelters that have been abandoned by other animals are frequently used by river otters, such as old beaver dens or riverbank excavations. On occasion, river otters use rock piles and log jams as dens. Some investigators have discovered nests along river and stream banks which river otters had constructed of aquatic vegetation. Mating activity usually occurs in the water, although there are reports of mating on land. The breeding season is usually late winter to spring. Litter size is between one and six cubs. The newborn otters have full pelage, but their eyes are not open and they have no erupted teeth. Females wean their young at about three months of age. Several predators, including bobcats, foxes, and alligators, have been observed dining on river otters. Humans also have made their impact on otter populations in at least three ways: habitat destruction, water pollution, and overtrapping.
Thanks for description - Animal life club