Ducks quack to communicate a range of signals with mates, competitors, offspring and predators. However, quacking is not the only means of vocal communication for ducks. Depending on the species and the sex, ducks can also squeak, chirp, hiss, grunt or whistle.

Male ducks are called mallards, female ducks are called hens or ducks, and baby ducks are called ducklings. Hens most often produce the distinctive quack, while mallards produce a comparatively softer, shorter call, or they remain silent. Ducklings produce a soft whistling sound to communicate distress.

A group of ducks is called a flock while in flight, or a paddling or raft team while on water. Alternative names for groups of ducks are brace and badling.