Budgie fighting

Make sure to provide enough space for two budgies. Female Budgies are more territorial and they need space even when they have a partner. If they are fighting all the time it may not be a well-bonded pair, and you should separate them.

How to help budgie to overcome his fear?

Every Budgie is scared of new toys, even new human faces. They always need time to adjust to new toys or even vegetable/fruit. So if your Budgie is scared of new toys, place your New toys outside the cage where he can see them, then after a week place the same toy inside but somewhere where is not present a threat to him. After a week or so he will get used to it and he will realize the new toy does not present a  danger to him.