Martins are small to medium-sized birds belonging to the family Hirundinidae, which also includes swallows. They are known for their agile flight and are often seen swooping through the air to catch insects. Martins typically have a streamlined body, long wings, and a forked tail, which help them maneuver quickly while flying. These birds are commonly found in various habitats, including urban areas, open fields, and near water bodies. They build their nests in cavities, often using mud and plant materials. Some species of martins, like the Purple Martin, are known for their social behavior, often nesting in colonies.