Small to medium-sized birds, with large heads, long strong bills and short legs. Most kingfishers spend long periods perched singly or in well-separated pairs, watching intently before plunging swiftly downwards to seize prey with bill; they usually return to the same perch. They eat mainly fish, tadpoles and invertebrates; larger species also eat frogs, snakes, crabs, lizards and rodents. Their flight is direct and strong, with rapid wing-beats and often close to the surface.