How old does a chick have to be to attach pinless peepers?

[CritterHill]

I'm happy to report that evil-chick was in with her siblings all day and not one feather was plucked. Maybe her few weeks of isolation was enough to break the habit?

They just moved out to a pen in the big girl coop so they can get used to each other. I'll keep an eye on the tomorrow, but my fingers are crossed.

I have the peepers here if I need them. I won't hesitate to use them once she is a bit bigger if it seems warranted.

Thanks for all the advice folks.