The 67 species of Herons, Egrets and Bitterns (Ardeidae) are medium to large sized birds with long legs and necks. They are a widespread family with a cosmopolitan distribution. They exist on all continents except Antarctica, and are present in most habitats except the coldest extremes of the Arctic, extremely high mountains and the driest deserts.

Almost all species are associated with water, they are essentially non-swimming waterbirds that feed on the margins of lakes, rivers, swamps, ponds and the sea. They are predominately found in lowland areas, although some species live in alpine areas, and the majority of species occur in the tropics.

The diet includes a wide variety of aquatic animals, including fish, reptiles, amphibians, crustaceans, molluscs and aquatic insects. The most common hunting technique is for the bird to sit motionless on the edge of or standing in shallow water and wait until prey comes within range. Birds may either do this from an upright posture, giving them a wider field of view for seeing prey, or from a crouched position, which is more cryptic and means the bill is closer to the prey when it is located. Having seen prey the head is moved from side to side, so that the heron can calculate the position of the prey in the water and compensate for refraction, and then the bill is used to spear the prey. Some species of heron , such as the Little Egret and Grey Heron, have been documented using bait in order to lure prey to within striking distance.