A bit about my situation first : We're fairly new to the backyard chicken experience. We built our coop early spring, which has cedar siding, roofing, is open on one side to let fresh air in via chicken wire and access is through a large window on a hinge. Nesting boxes, feeder, and 2 roosting perches are in this area too. An enclosed run is attached and the waterer is located there. We bought our three chicks in April and were told they would start laying in July. One is a leghorn, one is a buff orpington and the last is a rhode island red. All three thrived and have done beautifully. As predicted, the leghorn laid the first egg in July, quickly followed by the orpington and, to my relief, a couple of weeks later the rhodie finally laid her first egg. All three quickly fell into into a pattern of egg laying in the morning and afternoon, consistently laying every day. For some time now, we let the girls out in the morning and they scratch and wander about the enclosed yard all day and finally end up in the coop at night around dusk. However, the leghorn has been acting a bit strangely as of late and I'm concerned. She has always been the dominate female, leading the rest of the girls around, and for a while there, was laying at least an egg a day. Recently, however, the leghorn has stopped producing eggs at all. She won't even leave the coop when the rest of the hens head out to the yard for the day. She's been nesting and won't leave the eggs that the rhode island and orpington lay (their production has not changed a bit). A couple of times, the leghorn has laid a few double-yolk eggs, but now...nothing. Sometimes I'll kick her out of the coop and she'll scratch around for a while, but when my back is turned, there she is right on top of the other eggs again. All of my hens will let me pick them up and I checked her the other day - she seems alright. Could someone tell me what's going on here? I'm worried that she's sick... Thanks in advance for your feedback, s.