Nightjars are medium-sized nocturnal or crepuscular birds in the subfamily Caprimulginae and in the family Caprimulgidae, characterised by long wings, short legs and very short bills. They are sometimes called goatsuckers, due to the ancient folk tale that they sucked the milk from goats (the Latin for goatsucker is Caprimulgus), or bugeaters, due to their insectivore diet. Some New World species are called nighthawks. The English word 'nightjar' originally referred to the European nightjar. Nightjars are found around the world except in New Zealand and some islands of Oceania. They are mostly active in the late evening and in early morning or at night, usually nest on the ground, and feed predominantly on moths and other large flying insects. Most have small feet, of little use for walking, and long pointed wings. Their soft plumage is cryptically coloured to resemble bark or leaves. Some species, unusual for birds, perch along a branch, rather than across it. This helps to conceal them during the day.