At first, parents regurgitate pre-digested liquid food to their nestlings. Later, they bring partly digested food, and finally whole fish, frogs, snakes and other items. A growing heron or bittern will grasp the base of its parent's bill in a scissors-grip and wrestle with it. This triggers an impulse in the adult either to drop or regurgitate the food. All are migratory, generally breeding in northern areas and migrating south in autumn.
Some species migrate in flocks, some in small bands, and some individually.
Other herons occasionally visit Pennsylvania. The little blue heron is a migrant occasionally spotted in April, and later in July and August. Little blues are 22 inches in length, with brownish heads and bluish-gray bodies. These four species typically breed farther south or along the Atlantic coast. Snowy and cattle egrets nested in Pennsylvania during the 1970s and '80s.