Family Mustelidae, or weasel, which includes mink, skunks, and badgers Length About three to four feet (0.9 to 1.2 meters), with the tail making up about one-third of the total body length   Click “Real Player” or “Windows Media” for video primers on river otter behavior.    Downloads: Real Player | Windows Media Mothers and Their Young Otter litters, generally born in the late winter or early spring, vary from one to six babies, although two to four are most common. Helpless at birth, young otters, or pups, suckle their mothers’ rich milk and grow quickly. They stay with their mothers for about a year, usually leaving the following spring.   Pool Play Play is an important part of the life of river otters. Here, two young otters cavort in—and around—tubs of water in their play area behind Glenn and Jeannie Chambers’ house in Columbia, Missouri. The otters are using the hairless parts of their noses to push a plastic cup around, just as wild otters might play with live prey.   Wild Play The play behavior of river otters often involves repeatedly catching and releasing prey. They also wrestle, chase other otters, jump around, and dive for stones and other objects. In fact, river otters seem to make a game out of just about everything they do. Rolling in the snow helps otters dry their fur.