a couple of my hens started acting different when i stand above them or reach to pick them up. The get really low to the ground and stiffen up wil their wings kind of out.. one of them when they did this they like started to skae a little bit. i dont understand why they would do this, even after i pick them up they stay stiff and feel weird. not all of them do it only a couple. does anyone know what this might mean?