Why does Silver suddenly attack my ear when he is sitting on my shoulder? He doesn't bite hard, but it's annoying. I'd really like to know why. Do your tiels do this?

Maybe your ear did something that he didn't like lol. Or maybe he's just trying to get your attention. This is common behavior for cockatiels.

Rio used to always bite my ear hard for no reason lol

Do you ever wear earrings? Maybe he's interested in the really shiny thing. From my experience with cockatiels and shiny things, they either love them or hate them.

Bella usually flies to my shoulder and, if I am busy and not paying attention to her, she would bite my ear gently to tell it's time to pet her. Some other birds fly to my head and then they try to play with my new glasses (that have some sequins on the side). I discovered that glasses don't look new anymore, and I was so mad! so, I take off glasses as soon as one of those birds is on my head, they look puzzled that sequins are not there anymore, and instead, they try to gently bite my eye, probably thinking that they would get to the sequins this way.

Rio likes nibbling my ears as well. He tries to preen them but it's nowhere near attacking. He also likes to use it as a chew toy. Haha

Coco used to do that. He would be calmly sitting on my shoulder, when all of a sudden, he'd try to take chunks off my left ear. It was so frustrating and hurtful, but I tried to ignore it and he stopped doing it.

Beaker and Jaid both bite ears. It's just something they decide to do.

Zorro puts his beak in my ear lol.