The chickadees are a group of North American birds in the tit family included in the genus Poecile. Species found in North America are referred as chickadees, while other species in the genus are called tits. They are small-sized birds overall, usually having the crown of the head and throat patch distinctly darker than the body. They are at least 6 to 14 centimeters in size. Their name reputedly comes from the fact that their calls make a distinctive "chick-a-dee-dee-dee" sound.