hello! I'm new here. my male cockatiel is near about 3 yrs old and the female one is near about 2.5 yrs old. the male one is in breeding mood and he is checking the nest box. I'm not sure about the female, sometimes she behaves like she is in breeding mode, but when the male is whistling and go to her, she bites the male in an aggressive mood. so I'm confused if she is in a breeding mode or not. they also breed 2 times before.