This tiny heron occurs in swampy vegetation, brackish marshes and mangroves. It is most easily seen when it flies across open areas among the vegetation. When threatened, it will cling to vertical stems and freeze in position, pointing its bill upward and mimicking bull rushes and other aquatic vegetation. The Least Bittern gleans insects and amphibians from stalks and leaves and also catches fish and aquatic invertebrates at the water's edge. Its nest is made of sticks and placed near the ground or over the water in dense vegetation.