Sheathbills live in the Antarctic near the shore. There are only two species in this family, the greater or snowy sheathbill and the black-billed sheathbill.

Sheathbills are all white. They have short wings and a horny sheath that covers the upper part of their thick, conical bills. They are the only birds found in Antarctica that have non-webbed feet, which makes them poorly suited for life on the water like other bird species found in the Antarctic.

Sheathbills spend most of their time walking around on the ground looking for food. They usually only fly when they are startled or threatened or when they are migrating.

Sheathbills scavenge for food and eat carrion (dead animals), and penguin eggs and chicks. Their breeding season is at the same time as the penguin breeding season. They nest near penguins, and breeding pairs will often work together to distract nesting penguins so they can steal their eggs or chicks.