Hi, i have a speckeld sussex approx. 8 months old. She has always been a little weird, always by herself. Then a couple of weeks ago when all of our chickens were free ranging. The speckled sussex out of nowhere grabbed one of our buff silkies with her beak and killed it my snapping its neck. We immediately took her away and separated her by putting her in a crate in the shed. After 2 weeks we tryed introducing them again and she again ran directly for the other silkie. Thankfully we stopped her. She walks funny too, leading with her shoulder/crop area and waking almost diagonally. Right now she free ranges all day and we keep our other hens in the chicken run. We are going to cull her soon if we cant fix it. Could she have just snapped? Let me know what you think, thanks.