Learn how to join with and utilize a person's current "bad" behavior. Rather than telling a person they are doing something "wrong" and suggesting a fix, validate their current model of world, and change will occur "on its own." Many years ago my parents gave me a parrot. The first thing I learned is that parrots can be dangerous to be around. They can do major damage to your fingers and other body parts. At time, I was living and working with my friend Reeves Teague. He understood animals from a "country boy" perspective having grown up in mountains of North Carolina. Here is process I learned from Reeves, and modified over years.
1. Invite an attack with an open and loving countenance. The parrot is going to try and bite you no matter what, as a natural act of self preservation. Instead of trying to stop him from biting you, utilize his current behavior and encourage it. Wear something to protect your fingers, and invite parrot to bite you.
Welcoming and utilizing parrot's current behavior even if it is violent, is very much in spirit of Aikido and Ericksonian Hypnosis.
In Ericksonian Hypnosis you utilize client's "bad" behavior and join with and validate their current model of world, rather than trying to change client and give him message he is doing something wrong.
In Aikido when you encourage your counterpart to express themselves physically, and they attack you, they are actually following your directions, and doing what you have asked. At such times attack becomes definitely less violent, as attacker unconsciously realizes that on a deep level they are cooperating with you.
Whether activity be Aikido training or parrot training, when you welcome attack, attack winds up being a lot less vicious.
2. Encourage violence and tenderness at same time. Leave your finger in cage and encourage parrot to gnaw on it. With your free hand gently rub parrot's head much like you might do with a dog or cat. When you and parrot are tender and violent at same time, you are beginning to engage in act of play.