This article is reprinted from The Pet Bird Report , with permission from the author. Many parrots start biting as juveniles, when they start asserting themselves to see who in your family will be the flock leader. Of course, the parrot hopes it is itself.
Parrots start using their beaks to refuse a command, such as the 'up' command.
If the owner pulls their hand or finger away the parrot takes that gesture as a sign of submission. Some bite during mating season as a sign of increased hormone activity. While certain Amazon species have the worst reputation for this, other species, such as cockatoos and African Greys may also become hormonal biters during their breeding seasons. Males may become excited while displaying for their human 'mates' and grab your finger. Hens often become territorial about guarding their cages, as if the cage were a nest.