I do not believe that this is normal behavior for a bird. It would seem that it is experiencing some sort of distress, you should contact a veterinarian's office as soon as possible to try to keep your bird healthy.
you can t determinate if your bird is a boy or a girl if he likes to bite your clothes. if a cockatiel is a boy his tail will have patterns on it otherwise if it is a girl she will be plain.
they are protecting their egg.
play
About twice as hard as a Budgie.
playing
When a cockatiel flairs its tails and shows its wings, it means that something has frightened it. It is trying to make itself look big and threatening so that whatever it is afraid of will go away.
No but baby beardies have been known to bite each other's tail off by accident in play
No, they can be pulled of but the squirrel will probably bite you before then, or the tail can be cut off which I highly recommend not doing.
i need help with this question
No they do not
It must be seen by a vet as soon as possible. The leg might be broken.
yes