Birds spend a lot of time grooming. They preen. Small bugs can live on birds. Preening gets them off. It also removes dirt. Many birds also oil their feathers. The birds create the oil. It is made in a special gland. They get the oil on their beaks. Then, they coat their feathers with their beaks. Using oil is common in water birds. The oil protects feathers. It prevents dirt from building up. It also keeps out moisture
Preening helps make birds _________.