I came home from errands tonight to find one of my Polish chicks completely plucked of her top notch. Another one looks like she has had a few top feathers plucked too. I cannot tell who the culprit is. I have a mix of Silkies, EErs, Cochins and Polish. All but the Silkies are supposed to be pullets. They have plenty of room in their brooder. They are three+ weeks old. Everyone seems happy but gosh that was such a shock. I gave them some chopped up boiled eggs (protein seems to be what a lot of folks suggest?). Should I separate her from the flock? She's running around happy, etc. Would hate to make live alone but want to do what is best. Also what if anything really works to discourage this once it has started?