I was wondering if someone could help me with a problem I'm having with one of my Parrotlets. She is 2 years old and has suddenly become extremely aggressive with my other birds whenever food is involved. Even if she's not eating and another bird goes for the food dish, she will attack them viciously. She has even injured one of my other birds and I have had to separate her in her own cage. This is an entirely new behaviour that has developed in the last month and nothing I do is breaking it. She is perfectly fine and friendly with my other birds any other time. I really have no idea what to do with her.