My black australorp hen passed away unexpectedly about a week ago while I was away, she showed no signs of disease or anything. I’m worried for my 3 other hens, they all seem energetic and fine but one has stopped laying entirely, another has strange breakage in her feathers so she looks a bit skinny. I gave them some depurox about 3 days ago… haven’t seen any worms in stool though. They have chicken lice!