Our bird started hanging out on the bottom of the cage.He looks like he can't keep his balance. When he starts to fall over he starts to flaps his wings, thenhe will start to shake his head. There is nothing coming from his nose or eyes, and he is still eating. we have another bird with him and she looks fine. I do not have lots of money to spend on a vet and it is the weekend. Do you know what is wrong? What can we do?