There has been alot of changes the last week. We lost a hen, got two new chicks and my cat is pestering the two remaining hens. They have been reluctant to drink or eat treats (won't eat feed). The vet gave them a clean bill of health. I've never had chickens so stressed they wont eat their food or do much activity (unless I am nearby). I'm trying to make everything as calm as possible. What can I do to make them happy hens again?