i purchased 6 bk orpington baby chicks in may. One was injurded in back yard and died. 3 got sick one at a time, would not eat, could only stand one side, would just fall over. Put each one away from others, not picked on. 2 left now one has developed what looks maybe like a hump, white poop on rear and today she is not roosting. I can't figure what is going wrong. never had chicken in back yard before. let them out everyday. buy store food and put veg scraps out but will only eat grapes. any ideas of what is wrong? they are so pretty and fat.