Otters eat a startling variety of prey. Although fish is the staple of their diet they also opportunistically eat snakes, frogs, lizards, birds, eggs, small mammals, mollusks, crustaceans, and sundry other invertebrates. Their need for calories keeps them from being too picky. Despite their speedy metabolisms, otters live as long as dogs. the Oriental small clawed otters and the river otters are quite clannish and live in big playful groups.