Hi there. I have two cockatiels, a male and a female. I've had them for about a year now. The female is sweet and likes to come out and perch on my shoulder. She has never layed an egg. I'm a little confused about this.The male is really mean. He'll hiss at me when I put my hand in the cage and lunge sometimes if I get too close. He's also really mean to the female. If I have her out he'll call her to come back, but when I put her in he screams and lunges at her. I am wondering if it might be possible to introduce a new male cockatiel to them, and if he might bond with the female?