Poor Dandy is covered with pin feathers here. When new feathers come in they have casings that need to be removed for them to spread properly. Preening serves this function, but it's hard for a bird to preen around its own head. Dandy hates to be handled, but if she can't get preening from the other budgies we may have to capture her and give her a good head-preening for her own good, as those sheaths on the pin feathers can be extremely itchy and uncomfortable.
Oh, I know, but the only way for us to help is to catch her and preen her ourselves, which she hates; she's not a hands-on budgie like some of our birds. She will happily scurry up INSIDE my sleeve to hide, though!
I have to do that with my sassy budgie as well. Gosh! She doesn't like to be handled either. But she tries to deal with it by rubbing her head against her bell.
Dandy bites, so it can be hard to preen her. She and Bruce are both very hands-off types. Dandy does like to hide, though; we lost her once and found her hiding in a pair of pants, and several times she's scurried up INSIDE my sleeves when I've had to try to get her. She seems rather comfortable in there.
Very cute, though!