Why dose my cockatiel rock back and fourth when he is scared.?

Answer 1

It might be because it is just he way of expressing his scariness. They have ways of showing their feelings like us. He might be also trying to scare the other thing away since he might be not scared at all.

Answer 2

He does it to calm himself. Perhaps you could move his cage so that it is in a place where he does not become frightened as often.

Answer 3

to try to scar the thig it`s sked of away birds do thing like that thay also shak there toys